Freshwater Aquarium/Oops!


Hello Richard, I have a 29 gal tank which has been up and running for about 3 years.  Recently the landlord changed the water system which resulted in acidic tap water.  To combat this I changed the substrate in the tank to Aragonite "sand".  I changed the substrate on the 5th followed by 2-3 water changes due to EXTREMELY cloudy water (couldn't see more than an inch in the tank).  Fast forward to the 10th - fish have returned and seem happy.  Water still a little cloudy but not as bad. After testing the water I got the following readings: Ammonia 1.0 ppm, Nitrate 0, Nitrite 0, pH 8.2.  I added a dose of ammonia detoxifier (AmQuel) and QuickStart, but still have elevated ammonia levels at 0.25 ppm and Nitrite is now rising.  What should I do now to help my little guys?  Everything my LFS tells me seems to make it worse.  Thanks, Carl

Hi Carl

When you changed out the substrate, you destroyed all the beneficial bacteria in the tank. This caused it to start the cycle process all over again. The cloudiness you experienced was a combination of a bacteria bloom and sand in the water.

The best thing to do now, is 10% water changes every couple of days in addition to your weekly 25% water changes until the ammonia levels are down. I would avoid using any chemicals to reduce ammonia. These do not work and cause more harm than good, regardless of what the bottle or someone at the pet store may have told you.

Another thing you may want to do is put a sponge over your filter intake to keep sand out of the filter.

Hope this helps you, good luck!


Freshwater Aquarium

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Richard Hight


I own and maintain several freshwater aquariums from 2 to 180 gallon. I can answer most questions about freshwater aquariums, including setup, cycling, maintenance, compatible tank mates, feeding. Moving? I've moved fish both across town and across the country and can help you get your little aquatic friends to their new home safely. I know and have experience with most freshwater community fish, South American Cichlids and African Cichlids. I don't answer questions about Goldfish or keeping Goldfish with Tropical Fish. I also don't answer questions about keeping crustaceans (shrimp, snails, crabs etc) with Tropical Fish, nor questions about saltwater fish or aquariums. I'm not available to answer questions on weekends, this is when I do maintenance on my own tanks.


Many years of personal experience with community tank fish, semi-aggressive fish (Barbs, Tetras, etc), Angels, South American Cichlids and African Cichlids.

HSG 2010-2011 prof

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