I got the smaller micron socks. Had to put it inside a larger square sock as my square holders are just the tiniest too big for them.
Next step that's frustrating me is this freaking Hanna LR phosphate test kit. It's been months since I bothered testing for phosphate because of this issue. Test 1: 33 ppb P (about 0.1 ppm po4). After a water change a 1ml dose of phozdown (probably to small to do much in my size tank), test again. 44ppb P.
Do a dummy test with pure distiller water... 22ppb.
Glass vials are notorious for adsorbing small amounts of phosphate. In high end labs, they wash the glassware they use to run phosphate tests in hydrochloric acid regularly to remove it. The last time I was regular testing P, my "level" was predicted by how many tests I'd done, not what was actually in the tank.
Anyway I just acid washed and and dummy tested my vials again and I'm down to 16ppb with distiller water, which might be the actual amount in the water jug I bought from Safeway, but it still makes it hard to trust the test.
|