How to adjust the pH in your aquarium

The ideal pH level for planted aquariums is anywhere between 6 - 8.5
(Last Updated On: May 17, 2018)

What are the effects of pH in the aquarium?

High Alkaline

pH changes in the aquarium, even if small, can have serious health effects on your fish. High alkaline, aka basic water, can affect your fishes’ gills. If your fish dart back and forth, check your pH, as this is a common symptom of high alkaline and may result in fish death.

High Acid

An acidic aquarium can result in the production of excess mucous by your fish. This is due to an increase of toxic elements promoted by acidic aquarium water. Other observable symptom include fish gasping, hyperplasia (thickening of skin and gills), and eye damage. As with high alkaline, fish death can occur.

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How do I adjust the pH in my Aquarium?

How to increase the pH in the aquarium

A common method of raising the aquarium’s pH is by adding baking soda. 1 teaspoon of baking soda per 5 gallons is generally considered a safe amount for small incremental increases.

It’s best to remove the fish from the tank prior to raising the pH. Then simply dissolve the required amount of baking soda in some conditioned water and add it to the aquarium. Once the pH is at the desired level you can re-introduce the fish just like you would when you first brought them home from the store.

You should never make sudden and large pH changes, as this will have a severe effect on your fish. Start with 1 teaspoon per 5 gallons of water and slowly raise the pH incrementally. This will allow your fish to acclimate to the new tank conditions.

• add crushed coral 

• add dolomite chippings  

How to lower pH

Using peat moss is a common way to lower the aquarium’s pH. Simply put the peat moss into a mesh bag and add it to the filter. Peat moss will gradually lower the pH. With peat moss, it is likely however that your water will temporarily discolor. It should clear up over time and you can also use activated carbon to help it along.

Other methods of lowering the pH include:

  • Decrease aeration of the aquarium
  • Driftwood will soften the water and lower the pH
  • Increase CO2 levels (planted aquariums)
  • Adding RO water

What influences the pH in the aquarium?

  • The pH level can be different before and after water changes, especially if the pH of the aquarium water and the aquarium itself vary
  • Decreased aeration will lower the pH
  • driftwood will soften the water and therefore lower the pH
  • adding CO2 will lower the pH
  • high nitrates can cause the pH to drop
  • pollutants and waste in the water will lower the pH
  • crushed coral (substrate or ornaments) will increase the pH
  • hard water will cause higher pH levels
  • using a water purifier can lower pH levels (good with hard water)
  • soft water is generally low in pH
  • RO water has a pH of 6 or lower 
  • overstocked aquariums can be low in pH

Stability is the main factor, keep in mind that fish can adapt to a pH that is slightly off their preferred preference, it is the fluctuations that causes stress and fatalities.

The pH will vary during the day, it should always be tested in the morning or evening. Always ensure that the test kit has not expired.  

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91 thoughts on “How to adjust the pH in your aquarium

  1. Alfred Bon says:

    I have saltwater tank 15g..it has a reading of 0.20 ammonia, 0 nitrites, 0 nitrates and my ph level is low is there any chance to increase it i’ve added crushed coral a bit but not have been try the baking soda on it.. is my reading is safe although i’ve started it as it is and my fish are doing well. Thank you

    • Thilo
      Thilo says:

      You have to check your alkalinity levels. If the alkalinity is good, it could be a temporary shift. Marine salt mixes should provide sufficient buffering, make sure salinity is correct. The ammonia reading? Has the tank just been set up? If so, give it some time for the water to find its balance. Once complete, you can make adjustments if needed. CO2 could be another factor, try to air out the water before adding it to the aquarium.

  2. Nathaniel says:

    My alkalinity is nearly 0 and my ph is 6.6 my water hardness is 300 and I’m having trouble raising ph levels to a Good 7.8 for my freshwater chiclids what do I do?

    • Thilo
      Thilo says:

      Alkalinity determines your pH. In order to increase pH the alkalinity needs to be raised as well. This can be done by adding crushed corals (1/2 tsp per 10 Gallons, or baking soda (1/2 tsp per 25 Gallons). Repeat after a few says until the kH reaches about 5 or the pH reaches closer to where you want it to be.

  3. Erin Bee says:

    I have a snail only tank. I added a “wondershell” to the tank (measured appropriately) and after testing the water notice the pH dropped from 7 to 6! The GH IS 180 and the KH is 0!
    Upon researching I found that the wonder shell adds minerals to the water and can show false readings.
    I am concerned bc one of my snails shells seems to be thinning, and nitrate levels are currently 80!
    Should I try to lower nitrates or raise pH?
    Help 😢

    • Thilo
      Thilo says:

      The issue is the carbonate hardness (kH)
      You need to increase the kH to maintain the pH. You can use baking soda 1/2 tsp per 25 Gallons increases the kH by approx 1 (varies) or add crushed corals which is longer lasting. The level in kH you want is around 5 but it depends on your overall setup and requirements.

      • Erin Bee says:

        Thank you. Since I only have a 7 gallon tank I don’t think I’d accurately be able to dose the baking soda. Is crushed coral sold in pet stores? What would be the appropriate dosing?
        Do you know if the wondershell screwed up the water? or is it a separate issue? The Apple snails need calcium for their shells which is why the wondershell was suggested to me initially.
        All other snails I’m the tank look healthy. They even reproduced! Just the one block mystery has a thinning/cracked looking shelf near the opening.
        Thanks again for helping. The rest of the snails look fine.

        • Thilo
          Thilo says:

          Two tsp of crushed corals will be a good start, and yes it is available at pet stores. The kH is what buffers the pH the higher the kH the more stability in pH. It will take a few days for you to see an increase in kH and a rise in pH, but this is a good thing.

  4. Samantha Hughes says:

    Hi my KH is 3°d, should be 6-10°d and my PH was 7,2 but now 8 after adding PH up. I added this as the hardness was in the danger zone according to bottle. How can i balance these levels? All other results are normal

    • Thilo
      Thilo says:

      To ensure more stability you can use crushed coral or aragonite. A little goes far, 2 tsp for each 10 Gallons. Simply place it in a mesh bag, if the results are satisfying, you can release the content onto the substrate, or keep it in the filter, whatever works best for you.

  5. travis Nix says:

    Saltwater aquarium
    pH is at 8.4 and will raise up to 8.6-8.65
    I know mixed reef is good at 8.5 as a high but I can’t seem to drop it down far enough to keep it in likable parameters.. I tend not to chase it however based off my seneye I do monitor it.. ( I use test kits as well) .. I do dose calcium and mag to help balance the alk.

  6. Adrian says:

    My ph level is so high it killed my Pleco and most my fish I only have two platys left I have used ph down and it has done nothing my water is clear there is no food waste in it when I clean it I’m stumbled as I don’t know what to do I have a 68 litre tank it’s got to the point the foam pads in the top of the tank have been deteoriating lately too please help

    • Thilo
      Thilo says:

      Carbonate Hardness (kH) measures the buffering capacity and indicates how stable the pH will be. The higher the kH the more stable the pH. If your pH is persistent high despite adding pH down, you kH is likely very high. Reverse osmosis (RO) water has no hardness and can be used to lower the kH.

  7. Nancy K O'Leary says:

    The pH test color chart scale that came with my pH test kit had a number scale of 7.6 to 6.0 in 0.2 increments. My aquarium water was tested at 7.6 or higher according to the color chart. I added two applications of pH down (a 9.6% sulfuric acid solution) per day for two weeks which did NOT change the pH of the water but eventually all of the fish died. So why didn’t the pH change and why did the fish die?

    • Thilo
      Thilo says:

      Carbonate Hardness (kH) measures the buffering capacity and indicates how stable the pH will be. The higher the kH the more stable the pH. If your pH is persistent high despite adding pH down, you kH is likely very high. Reverse osmosis (RO) water has no hardness and can be used to lower the kH.

  8. Joanne Murdock says:

    I don’t know if I’m doing it right. The pH for my tropical aquarium is 6 or lower. Acidic. Its destroyed my plants.. Do I use pH up or pH down to get it to 7?

  9. Mel w. says:

    The article is mistaken. Increasing aeration usually raises ph, not lowers it; the reason is because increasing aeration helps raise the oxygen level in the water.
    Carbon dioxide lowers ph, oxygen raises it.

  10. Sherry Yurchisin says:

    Is there a fairly quick way to lower the acidity of a freshwater tank? I need to move some fish from a tank with high nitrites before they die and the only tank that could work has off the charts acidity. I’m at a loss as I’m new at all of this.

    • Thilo
      Thilo says:

      Lets assume your aquarium is cycling, or adjusting due to new fish or other circumstances? Add a pinch of salt to ease the nitrite poisoning. Watch the fish closely and perform a water change 10-20% per week. Keep in mind that the aquarium you place the fish in will also start cycling with ammonia/ nitrites being involved as well.
      Any pH level below 7.0 is considered acidic, not sure why you would want to lower the pH. Lets assume you have low levels (acidic) in the aquarium and need to move more towards the neutral area? Use baking soda. One teaspoon per gallon, add more if necessary. With no fish in that aquarium, you can add the baking soda until you have the desired pH.

  11. richard stanhope says:

    you guys use raise an lower interchangeably. how can high ph be low acidity or the reverse. high and low are irrelevant. i do not understand your products so can not use them

  12. Dude says:

    I have very hard water, after 30 drops the color still remained pink when I tested the water. I also have low ph around 6.2. I’m using a water softening pillow in the filter to soften the water a little, then I plan on raising the ph to around 7.0. Whats the best way to do this. I don’t want to use baking soda. After I get the ph to 7.0 I’m going to introduce co2 for the plants, that’s why I want to raise the ph. Also have low oxygen levels but I just put in a new airstone last night and the surface is really turbulant now. All the fish look healthy. Any advise would be welcomed please.

  13. joseph barakat says:

    hi all
    i have fresh water aquarium the PH 8.5 i tried put vinegar it drooped until 6.5 after 5 min return again to 8.5 i tried conditioner special to make ph low it drooped to 7.5 again after 5 min return 8.4 water cycling from 1 week ago i have very strong external filter only small Gravel i am using i dont know what should be do i am preparing for arewana fish but nothing work
    shall i change water ?
    please advice i am very confusing
    thanks

    • Thilo
      Thilo says:

      Check your tap water to see at what level your pH comes out. With the aquarium only one week old, your tap water, or well water, is likely at 8.5
      Best scenario is to use an alternative water source, this will keep your pH stable without you having to worry about.

      • joseph barakat says:

        i change almost 80% from the water i putted clean and soft water i bought peat balls and add to my filter ph reduce 8.2
        just now i bought driftwood after cleaning it i will add it to aquarium i hope it will reduce ph more

        thanks for replaying

  14. Annie says:

    Hello! My water from the tap (I have well water) tests at 6.0 on the API master kit. Am I to believe it could be even lower but the test can’t read it? One of my cycled tanks measures at 6.6 for PH. In that tank I have lots of wood as well as Fluval Stratum. My snails are showing shell erosion and I’d like to increase the PH. A friend suggests adding a mesh bag with crushed coral. How do you keep from stressing the fish when you do water changes? Am I supposed to treat the new water somehow before adding it to the tank that has the coral water?

    • Thilo
      Thilo says:

      The woods are leaching tannin, it softens the water, and that lowers your pH. The tannins can be leached out by soaking the wood in water. The water will turn yellow/ brown. Replace water and repeat until the water stays cleaner.

  15. lyanna says:

    Hi! I just got a 20 gallon tank I made sure I rinse everything well with warm and got water I placed everything in the aquarium used the water conditioner that came with the aquarium added one table spoon of sea salt recommended by a friend to use and filled it up first day the water was clear by 3rd day the water got cloudy so I waited another day and decided to change half the water only it was nice but following day is cloudy again and I still haven’t placed any fish in there because first I wanted to test the water the results are nitrate color is not in the chart, nitrite 3.0 stress, total hardness 300 very hard, total chlorine safe, alkalinity is not really in the chart the last color is a dark green mine looks more deep blue, pH 8.4 alkaline. I used the tetra easy strips. What can I do to make it safe and clear for my fish? 🙁

  16. Irene Jaramillo says:

    I have only 4 chiclids in a 55 gal. Just cleaned it out. I’m getting nast circle algae and I’ve checked my ph n Alk levels. Only the Alk level is low but I think it’s because of the water change. Help

  17. Jackie ansfield says:

    Having issues with mollys, gasping shimmering after bit of home work and water test seem to be ph is low only 6.6 to 6.8 how do I adjust this

    • Scott @ Algone
      Scott @ Algone says:

      Please see the instructions in the article above under the heading “How do I adjust the pH in my Aquarium?”.

  18. Christine Phillips says:

    My well water has good PH but when I add it to my tanks the PH go’s up. I have sand in my tanks so I thought it was the problem so I changed it out and did a water change by the next morning I had high PH again.. What can cause the high PH? I’m at a loss as what to do… the well water is about 7.2 for low and 7.8 for high. The tank water is past 7.6 for low and 8.2 for high

    • Jim says:

      Make sure you clean any mineral deposits and other contaminants from the under side of your hood. You should clean with white wine vinegar diluted 1/2 a gallon of water to 1/2 a cup of Vinegar. I had the same problem and could not figure it out. This could be your problem. Good luck.

  19. Donna Choice says:

    Hi , I’m currently using bottled water( rvom) in my fresh water aquarium because I’ve had a hard time getting the correct ph with the tap water. The bottle water is high in alkaline. I added ph tablets but I’d like to use bottle water because it’s cheaper…would it be okay to add distilled water get the correct ph.?

    • Thilo
      Thilo says:

      Destilled water has a pH of 7.0 but CO2 can lower the pH causing the water to become more acidic. You can always test the pH of the replacement water, which will give you a basis to work with. Make sure the water surface in the aquarium is disturbed by waves (from the filter outlet) this airs out CO2. Also keep in mind that bottled waters are not alike, switching to a different brand can solve the problem.

    • Thilo
      Thilo says:

      The pH can raise if CO2 is aerated out of the water. CO2 is generally already sufficiently aired out by the filters and water surface movement created by the filtration system. So unless the water is stagnant or has other issues that causes CO2 levels to increase, added aeration will not increase the pH.

      • Devin Soh says:

        I think you have a point. But may i know in what situations will aeration lower pH values? As i still cannot get this point clearly.

  20. Maria Delia says:

    Good day,
    Sir wgat really ph di the fish needed high or low? Gow about the water from a well is that safe to put in a tank or need to leave few days un a bucket.we have koi in a large cocrete tank and angrl fish, gold fish in an aquarium.please advised.Thanks more power

    • Scott @ Algone
      Scott @ Algone says:

      Most fish prefer a neutral pH of 7.0. Well water is usually safe to use, however, as with any water source you should test it for nitrate and pH before using it. Leaving water sit in buckets only helps dissipate chlorine, which should not be present in well water. You’re better off using a water conditioner to neutralize any heavy metals in the water prior to use.

  21. Jody says:

    I am new to the fish tank world and I can not get the phone to rise I have no problem with adding baking soda but I can not remove the fish please if there is any suggestions I would appreciate all it is to low and have lost 2 fish thus far

    • Thilo
      Thilo says:

      To raise the pH, you can use baking soda, or crushed coral. Crushed coral will be a more permanent solution. Both are trial and error, use a little of each and see what the levels are the next day, then adjust from there. Main issue is to take it slow, give it time, one or two weeks. Sudden changes are more dangerous than fish living out of the preferred pH level. No need to remove the fish in any case.

      • Sara says:

        Will refilling the water from a python from the faucet and then adding the baking soda in a cup of aquarium water then mixing and adding to aquarium water mess with the oranda goldfish?

  22. Sadie says:

    My ph level is at 6.0. I have 100 gallon tank and have mostly parrot fish. I have been told a happy level is 6.8. I have tried ph fix solutions with no luck. Any suggestions?

    • Thilo
      Thilo says:

      PH can be raised by adding crushed coral. Add slowly, one cup a day, measure pH and continue until you reach the comfort level.

  23. Lini says:

    Recently if have added a crush coral into 12 litre of tank. Initially my tap water and aquarium was at 5.5 ph the next day after adding coral ph spike to 6.5. After Three days later 2 of my cardinal tetra start to loss its colour. Do advise me on this whether i should remove half of the coral or is there any other remedies. I just check today the ph level is 7.0. This tank is just 1mth old

    • Thilo
      Thilo says:

      One factor that causes fish to loose color is stress. Changing the pH from 5.5 to 6.5 and then 7.0 is a stress factor. The pH is perfect now, so the fish should recover and re-gain the color.

  24. lisa says:

    hello, could someone please help me understand if I am doing this right , I have a 125 gallon fishtank with 6 beautiful oranda goldfish in it, running o it is 2 fx6s, now my ph out of tap is 7.2 maybe 7.4 hard to tell useing apl test kit. my tanks water is 8.0. so I airrate my water to match the tanks water before doing water changes so that the ph is the same, I read that this is the way it should be done for the fish ,I have very hard well water. I also change out around 50 gallons of water every 5 to 7 days depending on how high the nitrates are , I do not let them go over 15/20 ppm, I was wondering if I am changing out to much water each week, with me having such a high ph level , and my water being so hard, I half to be very careful when cleaning my tanks filters when needed cause I’ll get small readings of amonnia and since my ph is high and the hard water makes it more toxic for my fish, I think any way, if I understood what I have been reading , it’s so confusing. I do have a few small pieces of driftwood with some plants ties to them and a sand substrate, but that isn’t the cause of my water problem, only cause I used to keep bear bottom for the first few years of keeping goldfish, and no plants or sand and everything with the water hasn’t change , my test are always the same , ph , gh , kh, it never changes .the only thing that changes is that if I mess with the filter cleaning to much , I go though a mini cycle, for about a day or 2, and this tank had been set up and Cycle for a few years now ,,, when that happens the amonnia is never to high , but having such high ph and harder water makes it more toxic for my fish, even tho its so low, I don’t understand what I am doing wrong , and I do not want to play around with the ph, or adding chemicals to the tank , I want to keep it natural for them and not hurt them in any way, it just breaks my heart to think that it could be me who is messing things up with the water , maybe by doing to much of a water change , but the nitrates are at 15 / 20 I was told that they shouldn’t go any higher than that, I do a 45 to 50 gallon water change, airrated in buckets to get the right ph for the tank so I don’t understand what I am doing wrong ,

    • Thilo
      Thilo says:

      Water that is high in hardness will have the tendency to have higher pH levels. In order to lower the pH with hard water is to change the water source, or to accept the higher levels and keep fish suitable for that environment. Distilled or R/O water to mix with the tap water would be one option. Oranda’s accept a wide variety in pH so they will adapt and be more happy as compared to an ever changing pH level. On water changes, these should not exceed 10-15% every other week.

    • Scott @ Algone
      Scott @ Algone says:

      That depends on individual tank conditions. We recommend that dosage as safe without a sudden large increase. You should allow for one day after adding the baking soda, then checking the pH level and repeating the process as necessary.

  25. Danielle says:

    Hi i have cycled my tank and had the water tested it is ready however my ph is high despite using treatment in the water. We used love fish tap safe. The ph is still reading 8. Is there anything else i can add to lower the ph before i add guppys. Thank you

    • Thilo
      Thilo says:

      Do keep in mind that the pH fluctuates slightly throughout the day. Also if you had it tested, the time from when you remove the water sample, to the time when the water is tested, pH can change. Testing pH should be done on a regular basis, so it is a good investment to have a pH test kit on hand. With that you can also test the water you are using for water changes to determine if the pH is high from the water source, or if the cause of the higher pH is within the aquarium.

      Changing the pH value can cause instability and cause more issues. A pH of 8.0 is not really that bad for guppies and even with the pH being slightly out of the comfort zone, it should not be a problem.

  26. Helen says:

    I’ve recently added baking soda to my 50 gal tank to increase the pH. I used half the recommended 1tsp per 5 gal amount and found my pH to increase from 6.2 to 7.2! I had to quickly add drops to my tank to lower the ph as this increase is huge. If you are trying to increase the pH I suggest you add 1 tsp per 25 gal not one per 5 gal as this steep of an increase may shock the fish.

  27. Heng says:

    yesterday i have bought the RO filter set(brand :micron 50gpd) the water goes through the filter but im not satisfied with the high PH but the TDS result is very good we can get 3 PPM but the PH is 9.0 What is the reason for this is it my filter or because of other reasons? our house tap water does not go through filters the result is 120 PPM,PH is 7.0

    • Thilo
      Thilo says:

      If you have an alkaline water filter included in your set, it will increase your pH. Please check with the manufacturer for details.

  28. Angela says:

    One of our fish died and after testing the water realised the ph level was around 12 plus the pump wasn’t working. Changed the water, and retested it after adding water conditioner and instead of lowering it, it’s around 14 now. New pump is on the way. What would you recommend? I thought I was helping but seem to have made it worse.

    • Thilo
      Thilo says:

      The pump is definitely a vital part and might just solve, or at least contribute, to correct the cause that killed the fish.

      I have doubt about your pH readings. A pH of 12 is that of bleach and there is literally no natural way for the pH to reach levels of 12 or even 14.
      Your test kit might be expired or the chemicals have been compromised and provide false readings. I strongly recommend to purchase a new pH test to see where the actual values are.

  29. Ano says:

    Mine was because of aeration. Whenever I try to turn on my bubbles maker, the following day my fishes looks stressed and ph drops.

  30. DIANA L BROCK says:

    I can’t keep my ph levels lower than 6.8 so I used baking soda, 3 teaspoon for 20 gal tank. It shot up my ph to 7.6 and possibly higher. Went to feed them only find 2 guppy dead. I exchange 2 gal of dechlorinated water. It didn’t change not a bit. Now I’m going to change 4 gal of treated water cause I don’t know what else to do.

    • Thilo
      Thilo says:

      It is not the level of the pH that caused issues it is the rapid change. If you attempt to lower the pH, please take your time. You can use distilled, or R/O water one gallon at a time to achieve that.

      6.8 is actually an acceptable level for guppies. Check on the carbonate hardness (kH) which will indicate the stability of the pH. Your current level of 7.6 is also within acceptable parameters. I would just leave the pH alone, it will adjust itself. Again kH is the determining factor.

  31. Nicki says:

    Please do not use any baking soda!!!!!!!I’ve spoken with many fish experts and baking soda is used to euthanize fish in most pert stores. It deprives them of oxygen. IT WILL NOT FIX your Alkalinty problem.

    • Thilo
      Thilo says:

      Baking Soda is harmless and has many benefits in the aquarium. Yes, it can be used to anesthetize a fish and in consequence euthanize a fish, but so can many harmless substances. It is the quantity that makes it beneficial or detrimental.

      The dosage to anesthetize a fish varies given the species, but used at 1000 mg/ L it is a fish anesthetic but insufficient to euthanize a fish.

      In a standard 20 Gallon aquarium, you would need to use 76000 mg/L to anesthetize the fish, but only a fraction is needed to increase the pH quite effectively and without any short or long term harm. On the higher end it would be 1500 mg/L to raise the pH in a 20 Gallon aquarium.

      In conclusion: baking soda is quite safe to use.

  32. Deborah York says:

    bought algone about a month ago,have changed 25% to even 50% of my 30 gal. tanks water & have used two of the algone packs (bought 6pk box) & still my nitrates are over 40ppm, its not working…what’s goin on with my tank!

    • Thilo
      Thilo says:

      Algone does not influence the pH levels. The article above just offers solutions depending on weather you want to lower or increase your pH level.

      In reference to pH, higher nitrates are not really in direct relation. Nitrates likely indicate less than ideal water conditions probably caused by a lack of maintenance, overfeeding and or overstocking. These “symptoms” can of course in part influence the pH and vice versa.

      Large or frequent water changes should be avoided in general. Water changes can influence the pH depending on the water source, but large water changes will effect the pH regardless of the source.

      Alkalinity (buffering capacity) is what you should test for to check the stability of the pH.

  33. Lauren says:

    I have very hard tap water, and thus a very high pH. Would mixing some filtered/distilled water with my tap water at each water change be a good solution, or would peat moss be better? I’ve been keeping African cichlids so the high pH hasn’t been a problem, but I’m setting up another tank for fish that need a lower pH.

    • Thilo
      Thilo says:

      Distilled water will work so will RO water (available at pet stores) Distilled water is around or sighly lower than pH 7.0 while RO water is well below pH 7.0

    • Keith Procter says:

      Adding RO water won’t change the pH by much, if at all. Since the pH is driven by the aqueous “contaminants”, and those will still be present at about the same concentration. The contaminants in your case are likely mostly calcium and similar elements that cause the pH to be high, and the water basic. What adding RO water will do is reduce that alkalinity of the water. Alkalinity is a measure of how difficult it is to change the pH, or how stable the pH is. The higher the alkalinity the more stable the pH, which is a good thing, if the pH is what you need it to be.

      The best option is to use RO water and a pH 7.0 buffer (or slightly higher), but if you don’t have RO water available, then tap water with more buffer. The buffer is a mixture of complementary chemicals that work together to stabilize the pH.

      On the flip side, if you were looking to raise and stabilize the pH, then a marine or cichlid buffer is better than adding baking soda because it stabilizes the pH. You can use baking soda to approach the target pH, but having a buffer makes it harder for the aquarium to move away from that target.

  34. Dmitriy Yakovenko says:

    Thanks a lot for help with PH issue. I tryed many different fancy potions, lol, but can’t fix the problem. Backing soda works! Fish became a life in a couple hours. Amazing! Thanks again.

  35. EW says:

    I have Banded and Gloriosis sunfish with a PH of7.8 or possibly higher. Will natural Peatmoss bring down the PH to the 6is range–Say 6.2 tp 6.8. I’m currently using rain roof water as the liquid source.

    • Thilo @ Algone
      Thilo @ Algone says:

      Yes, peat moss will lower the pH of the water, so will R/O water (mix it with regular water to achieve the pH you desire). Please take your time in lowering the pH as it might shock the fish/ inhabitants if done to abrupt.

  36. Cecilia says:

    I have 2 goldfish in my 10 tank. Sadly, they both died, after just one month. My record was not so bad before, having had a fantail ryukin survive a full 5 years. Then I got the new goldie plus a bulging eyed black one, who had bubble eye disease –>For ryukin goldies, the PH level is supposed to be high, yes? It is now at 7.0. Supposed to be at 7.5, blue. Should I just add 1 teaspoon of baking soda, twice? Before getting new fish?

    • Thilo @ Algone
      Thilo @ Algone says:

      Baking Soda will increase the pH, but crushed corals or sea shells are more of a long term solution. Use 1/2 cup for every 20 Gallons and make adjustments from there. Corals and sea shells release calcium carbonate, which increases the pH level.

  37. Keith says:

    I have discus in my fish tank. My ph is 7.6 I tried peat moss , driftwood,I don’t want to try chemicals because I want to do everything natural.also I have plants inside my tank.

    • Scott @ Algone
      Scott @ Algone says:

      Using peat moss and/or driftwood are the most common methods of naturally reducing pH in the aquarium. If those didn’t work you can also consider using R/O water as this can help stabilize and keep pH at a constant. Carbonate hardness (KH) of the water determines how stable your pH is. Lower KH will result in lower pH. You can lower the KH with R/O or distilled water. We generally don’t recommend this unless it is absolutely necessary. Because big swings in pH are usually fatal for fish, only very small incremental changes should be attempted. If you take this route be sure to monitor the water parameters carefully, and adjust the pH very slowly over the course of days.

  38. Thilo @ Algone
    Thilo @ Algone says:

    Aeration is listed as a part of several options to lower the pH not as the exclusive solution. The pH is more complex and the solution to lower the pH needs to be applied based on the individual circumstances. Aeration itself does not have a significant impact on the pH within the aquarium.
    In your example of aerating a bucket of water, if the pH rises, it simply means that the pH is unusually low for the alkalinity level.

  39. Kc says:

    Increasing the oxygenation of water without adding co2 raises the ph of tap water, it does not lower it. When you put an airstone in a bucket & fill it with tap water with a ph of 7.8 & leave it aerating over 24hours the ph goes up not down.

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