I have added cheto to my sump on three different occasions, and each time it totally disappears. Don't know what happens to it. but it is not there.
I have a nice coat of red and white scum on top of the water in my sump, don't know why, but at least it stays in the sump.
The nitrates are at 100, this is with two different test. So I doubt they are wrong. It has been this way since the end of Oct. I did get a 20 once about a month ago, but I think that one was wrong now. I tried water changes like crazy, 2 and 3 a week, no good. I was told to just leave it sit and see if something would take hold and fix it self. So I haven't done a water change for 6 weeks, still no difference. I've tried to vacum the sump, overflow boxes where I see alot of junk building up. Still 100.
I've tried for the longest time to get my alk up. But it just wont go above a 3.00. The highest I have been able to get it is around a 2.64. I tried Randy Farley calculator. I spent about a month adding 2 teaspoons baking soda twice a day, 2 in the morning and 2 in the evening. After a month, it still wouldn't budge. Then I tried the Bionics. Two of the dosing caps every night. For the last two weeks, still nothing. As of this morning my alk is 2.29. which I know is way low. The only thing I can be thankful for is no one has died yet. Well the SPS's didn't make it. But the softies, anemonies, fish and snails are all good so far.
I guess it is like living in LA. after a while you get used to the smog.