2 weeks after I switched from 136 to 68 watts over my 30 gallon cube I decided to test nitrates -- Lamotte kit. I have to admit I have NOT been testing at all since EI so I can't offer a good comparative result, but.. in the morning BEFORE I would have dosed 1/4 teaspoon my nitrates on lamotte were darker than a 10 and the 10 needs to be multiplied by 5.5 to get a number that correlates to other testing kits. I figure I was at about a 60.

Everyone was doing well, except for some thread algae.. but 60 before dosing seems excessive, so I did a water change to cut it in half, did not dose more.. and I will try dosing 1/2 increments of ei.

Tom? weigh in ?

The first step when testing for nitrates and phosphates is to calibrate the test kit. Mix some DI or distilled water with enough KNO3 to get a known 100 ppm, for example of nitrate. Check it with the kit. Then mix some of that water in equal parts with DI or distilled water, to get 50 ppm and check that with the kit. Repeat until you are below the range of interest. Now, you will know what your test kit readings are telling you. The kit may be dead on right from the box, but it may also not be.

maybe.. but I have to say I have used the kit before ei and always showed fairly low readings. all the way dark, seems to be saying something even if it is a little off. and it is one of the good kits.


I have cut my light in half.. that must have some impact.

"I have cut my light in half.. that must have some impact."

Not quite so much as you might think ! Once you exceed optimum radiant illumination the "Law of Diminishing Returns" prevails.

Congrats on the Epiphany. Prof M