High Nitrates and Phosphates, Tried Everything I Could Think Of

TheFishBoys101 · Jun 17, 2020

Hi, I recently bought a tank off of craigslist for a great deal, but it was in bad condition. It came with 6 fish, and only 3 made the move, a porcupine puffer, an azure damsel fish, and a blue tang. One of the fish that did not make it we never found, a six line wrasse, which I think may have died inside of a piece of live rock that is still in the tank. Anyway, as the title says, after testing the water with an API test kit, the ammonia read 0.25 ppm, nitrite 0 ppm, but the nitrates were 160 ppm, the max that the test kit went to, and the phosphates were 2.0 ppm, even though all of the water we added to the tank after moving was freshly made except for about 10 gallons. The live rocks that came with it had cyano all over them, because there were no powerheads. So the first this we did was get some powerheads and it all disappeared, but it revealed a lot of green hair algae hiding under it. Just some extra info, it came with a sump that had a 7" filter sock and a reef octopus classic 200INT 8" Internal Protein Skimmer that is still working well and in good condition. I also added a lot of ceramic bio-media for bacteria. Still, after about a week, the test results remained the same. I did 2 40 gallon water changes (it is a 120 gallon tank with about 15 gallons in the sump) and after the first water change I waited an hour before testing, but the test results remained the same! And the second water change results read the same except for the phosphates being 0.5 ppm, but after a day they rose back to 2.0 ppm. And, to be sure the test kit was not defective, I tested the water before I added it to the tank and it read 0 nitrates and 0 phosphates (I do use RO/DI). After that I started to dose nopox and vodka everyday for about a week, and the results are still the same. Some ideas I had that I do not know would work would be to add a refugium or a clean up crew, which I would be willing to do if it would prove beneficial. I also do not believe I am overfeeding because I feed the puffer a clam 3 times a week, and I add a small pinch of pellets for the other fish 5 times a week, but I may be wrong. If you have any ideas or questions please let me know!

Randy Holmes-Farley · Jun 17, 2020

I'd be surprised if the nitrate is really that thigh yet, but it is not an emergency either way.

If the ammonia is really that level (may not be with that kit), I'd try to protect the fish with something like Seachem Prime for a bit to let the tank cycle try to catch up to the ammonia.

Lowering phosphate will be a long slow road due to the large amount bound to rock and sand. Something like lanthanum may be your bet bet. Water changes will not do it.

TheFishBoys101 · Jun 17, 2020

Ok, I can try another kit and see if the test results are the same. Do you have any suggestions? Also, is there a specific brand of lanthanum that may work best? And do you think a refugium would help at all? Thank you!