How to Know if Your Aquarium is Out of Balance

African Cichlids in aquarium

Did you ever look at your aquarium and notice that the pH levels were off, or that the nitrates skyrocketed over night? Not likely! These things can not be seen. Tests are needed to determine the levels of the most life sustaining values.

Nevertheless, the behavior of aquarium fish can give us an early indication that something in our tank is out of balance.

Here are a few things to watch for:

  • Fish hover at the bottom of the aquarium with little or no movement. Red gills may also be observed. This may indicate that ammonia is present and possibly at lethal levels.
  • If your fish can be seen gasping for air at the aquarium’s surface, this is generally associated with high nitrite and nitrite poisoning. Nitrite poisoning inflames the fishes’ gills making it difficult to breathe.
  • Gasping, darting and irritated gills can be caused by low pH levels.
  • Frayed fins along with whitish deposits at the water surface and on the filter equipment may indicate high and rising pH levels within the fish tank.
  • Darting and fast breathing often indicate residual chlorine is in the water. The same symptoms may be observed with chloramine with the addition of the gills turning brownish.
  • Fish not eating, hiding, and showing discomfort generally indicates a low and failing water quality.

If your fish display any of these signs, test your water immediately and take corrective action.

Also see our post about general aquarium water parameters!

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I have recently gotten brown spots showing up around my tank and I believe it could be a diatom bloom of some sort, i’ve taken it off my driftwood by sprayin the driftwood with 3% hydrogen peroxide but it doesnt seem to wanna come off the walls of the tank


Not sure how the driftwood plays in, but diatoms can be successfully controlled by removing silicate from the water. There are numerous silicate removers (aluminum oxide) available for you to choose from. Water changes should be done regularly to dilute the pollutant (please make sure your water isn’t the silica source). You can stuff polyester fibers (pillow filler) in your filter which will trap a lot of debris. Replace every 24-48 hours.
When cleaning the glass, use a sponge or polyester fibers (rougher) and scrape upwards rinsing the sponge/ fibers every other swipe.


I have a cherry red shrimp, I have this tank for 8 months and so far i have not encountered any problem, but recently there are tiny worms crawling inside the glass and on the soil, the worms are white in color and around 5mm long. When i try to catch it the worm retracts into a smaller size. Those ones that is on the soil immediate dig in. I have ask around about it where did it possibly came from, most informed me that i might have put new plants or accessories that might have already been infested but… Read more »


Your description would fit planaria/ detritus worms. These are not harmful to the aquarium or fish/ shrimp. In fact, these worms might have been n your aquarium for quite some time. The increase in numbers is based on available food. Planaria/ detritus worms feed of uneaten food and detritus in the aquarium. Make certain that you are not overfeeding the fish, or the aquarium (in case your bio load exceed the tanks limit). Vacuum the gravel with each water change to remove uneaten food and detritus. This should solve the issue.

Anne Di-Palma

hi i have a salt water aquarium. the problem i have is that my tank gets large reddish marks on the glass! what causes this & what can i do as no matter how much clean it off it just reappears more or less over night.

If it is hard to remove and dark red/ purple, then it could be coralline algae. This algae grows predominantly on the rocks and glass and is quite desirable as it will retard the growth of the more unwanted algae species. It is a keeper. Another species that grows on the substrate/ glass and eventually covers all is the red slime algae. This algae is manually less hard to remove has an oily touch, tends to grow in sheets and can have a pungent smell. Giving the fast growth rate, this is likely what it is. Please use the site… Read more »

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