[Magickiwi]

Originally Posted by asylumdown

Normally I don't pay much head to nitrate and phosphate tests, and I normally only test the major ions once every couple of weeks. I'm paying extra special attention right now because things were so unbelievably out of whack, and then I took everything offline, so I'm doing all this testing to get things back on track. Once all my systems are back in place and my auto-dower is dialled in I'll probably go back to hardly ever testing.

And I'm going to stop trusting my hanna checker. With the rowaphos in there (and I used about 15-20% of the amount I would normally have put in if it was just regular bulk GFO), I was seeing a steady climb every day. I changed out the Rowaphos last night because I thought that maybe with such a small amount in the reactor it had honestly already been exhausted, but this morning it measured 0.21 after the conversion to PPM Phosphate, which shouldn't be possible unless the Roawphos was actually contributing phos rather than removing it. I've been using the same glass vial for each test though, and right after I got the 0.21 result, I swapped out the vial for one of the vials from my calcium kit and got a result of 0.008ppm phosphate.

I think my vial has been getting imperceptibly stained by each sequential test. I gave it a thorough wash with a bottle brush cleaner and laboratory soap two days ago, and I empty and rinse the vials with distilled water immediately after each test, but it's apparently not enough. I don't know how else to clean it, and it looks spotless to my eyes, but when one vial gives you 0.21ppm and another vial gives you 0.008 with the same water following the exact same protocol, it makes me not trust any of the results if the equipment alone can contribute such a wide margin of error.

As for the nitrate tests, today it was 2ppm. It's been a clear and steady increase since I took the pellet reactor offline and stopped doing massive daily water changes. More than anything I think it's just interesting to see, as my tank has never not had pellets on it so I really had no idea what it would do without them. I don't necessarily trust the numbers exactly, but I do trust the relative colour development which indicates that my nitrates are definitely rising. The Red Sea nitrate kit uses the same reagent protocol as my faculty's analytical hydrogeology lab (which really means it shouldn't be going down the sink as there's cadmium in it, but Red Sea doesn't tell you that), and while my lab would use a Hach spectrophotometer to measure the colour exactly, you can get a really good qualitative idea of the amount of nitrate in the sample just by looking at how red/pink it turns. And every day since wednesday my sample has been progressively pinker than the day before.

I use muriatic acid to wash my sample cuvettes. And I also think that they get stained after a few tests so that you can't trust the readings. I've dosed the Carib-Sea phosbuster twice in the last two weeks and according to the hanna checker my phosphate didn't go down at all the day after etc.