Fixing a community tank in the broadest terms

The Community Tank is Having Trouble. 

Do this:

Check pH 

Drop the water level 50%. 

Pull your sponge filters and wring them out in the *fish tank water* not under the tap.


Refill the tank to 90%.

Apply at least a teaspoon of baking soda.

Go out to your pond, pull out some sponge material from the filter, and wring it into a bucket. Get a lot. if it is a dark, greenish-brown, then you win.

Slowly put at least a quart (but preferably a half gallon) of greenish squeezins into the tank. 

⭐️ It is better for the fish if you put the squeezins in a container with a small hole punched in it. And let it trickle into the system, instead of flooding it. 

Let your ‘wrung-clean’ filters pick up the bio-active ‘goo’.

In the morning, add another teaspoon or two of baking soda.

Author: Dr. Erik Johnson
Dr. Erik Johnson is the author of several texts on companion animal and fish health. Johnson Veterinary Services has been operating in Marietta, GA since 1996. Dr Johnson graduated from the University of Georgia College of Veterinary Medicine in 1991. Dr Johnson has lived in Marietta Georgia since 1976.