I can't seem to keep up with degrading water quality. Can you help me figure out what's wrong?
In a 180 gallon tank I have:
- A partition
- 2 Canisters SunSun HW-3000 (rated 793ghp each), such that there is flow across partition. In those I have polyester floss, medium-fine filter foam, and a bunch of plastic kitchen scrubbies. (no porous biofilter media though...)
- Natural "peace river" gravel, inert rocks, quite a few plants.
- 8-inch Oscar
- 6 congo tetras, 9 silvertip tetras, 6 phantom tetras, 4 hillstream loaches, 20-ish guppies, 2 juvenile pearl gouramies, 5 amano shrimp, 4 dwarf crayfish, 1 mystery snail, some pest snails
If you estimate conservatively that the smaller fish are average 2 inches each, then you still only have around 100 "fish-inches" in a 180 gallon tank. I used some other online calculator that also suggested I was not anywhere near being overstocked...
The oscar eats perhaps 20 pellets / day, the other fish are fed once per day and they consume all food fairly quickly except about 10-15 omega shrimp pellets that are consumed a bit later. Also some repashy that disappears over night.
I use a GH
mineralizer and soft tap water at about ph 6.6.
I change just over 25% water each week, and rinse out the canisters every 2-3 months. I vacuum the gravel that is accessible, but much is covered by plants and rocks. In the past 6 months I have skipped one water change, and also my most recent water change today is 4 days later than usual.
I had an issue with canister prefilters that temporarily raised the ammonia 2 weeks ago, and I solved that with double water change and Seachem Prime and the water later tested fine... I removed the prefilters and have had good flow since then.
Today my PH was down to 6.0, at least 2 of my fish have fungal growths and nitrates are around 30-40ppm (in the past I was doing 10-20). That just seems excessive for 10 days.