1. Can I use cat litter as a amonia absorber?
2. If I put ZEOLITE into my tank and it absorbes the amonia, does that mean
that there won't be any amonia to break down into nitrite/nitrate? Does
that mean that I am not creating bacteria in the filter?
3. Can I put ZEOLITE as bottom gravel in my 160 gal. pond?

Now for my problem question???

1.) I have 4 koi that grew in four months from 4" to 8" in my 55 gal. fish
tank. Water quality was good (Amonia-0, Nitrite-0, Nitrate-40). The last 5
or 6 times I cleaned the filter every other day because the water return
(circulation) was being blocked by sediment. Apparently the water quality
was being maintained by the bacteria in the bottom gravel since there was no
filter circulation (fish survived due to good aeration).

First question: Does the gravel bacteria theory make sence?????

I built a 160 gal miny-pond down in the cellar. I also designed and built a
drip filter (BIOBALLS media) which by theory is large enough to keep the
pond clean. I moved my 4 KOI (now 8") from my 55 gal. fish tank to the
cellar pond. Many of the BIOBALLS were taken from the previous 55 gal.
filter. I know that there probably is not enough media to take care of the
fish load but I was hoping that it would slowly balance out. Amonia going
up to 1, Nitrite-0, Nitrate-2-5 ppm). Did three 85% water changes in three
days but amonia levels are still up.

Next question: Can I use some of the gravel from the 55 gal. tank as bottom
gravel for the 160 gal. pond to help in controlling amonia?

Will ZEOLITE gravel work?

Now for the final question: If the water amonia reading is 1.0 and I change
85% of the pond water then wht does the next water test show the amonia
still high. I would think that changing 85% of the water should reduce the
amonia level by at least that amount. Next day water change same situation,
and the next.

By the way...fish as at bottom of pond but still alive...

Rich