Nitrite levels

Question
I have two questions, are power heads on a sponge filter or undergravel filter better?

This tank has only been set up for about 2 wks. 29 gallongtank.  2 small  oscar's and two algae eaters. Undergravel filter.

We have been monitoring our ammonia and nitrate and nitrite levels every other day.  Today our 29 gallon tank spiked at 5.00 for nitrite all the others are fine.  What could be causing this?  Also the water is cloudy and we have changed more than half the water 2 day's ago.  When we replace the water should we be using water from our established 180 gallon tank? or tap water?

Thanks for any help.  Hopefully I covered everything here! LOL

Answer
Hi Vickie;

Power heads could be used on either one but not for a tank with oscars. Undergravel and sponge filters are not adequate for them and will become useless very quickly because of the massive wastes that oscars produce. You need a power filter or canister filter and a much larger tank too. Those babies can grow to their adult size of 12 inches or larger in just a few months. Oscars will render an undergravel useless anyway because they constantly excavate the gravel that is supposed to cover them. Sponge filters will get hopelessly plugged very quickly. Just not a good situation at all.

The nitrite spike is because the tank is so new and still going through the break-in period. The break-in takes about 6 weeks. Here is a link to my own web page about the break-in that will answer many of your questions;

http://www.xanga.com/Expert_Fish_Help

The nitrite spike is so high right now because there is just too much waste in the system too soon. Change 25% every day for the next several days to help the fish survive. Use conditioned tap water. There is no benefit to using old tank water. The beneficial bacteria that your new tank needs is not in the water, it is attached to the filter and in the gravel. Adding some gravel from the established tank would help more. Add more air too with bubbles from an airpump and an airstone. High nitrites cause the fishes' blood to change in chemistry so they can't absorb oxygen very well. Aquarium salt helps them with that so use it until the tank is stable, if it ever gets there. The inadequate filtration problem may prevent it from stabilizing. Cut back on food so there is less waste going into the system too.

To get fish safely through the break-in period there should be "one inch of fish for every 10 gallons". If one of your fish is about 3 inches long, it should be the only inhabitant in your 29 gallon until the tank gets through the break-in. Once it's done you can slowly add new fish, three inches a week, until it is at a safe maximum population if that's what you want.

I hope they do okay...

At Your Service;
Chris Robbins