Understanding How Test Kits Work,
by Craig Bingman PhD
http://www.animalnetwork.com/fish2/a...io/default.asp

wet/dry filters are nitrate factories because this type of filter stops at the aerobic stage of filtration (nitrification), and lacks the anaerobic one that causes the de-nitrification. Because the wet/dry is aereated, it's oxygenated. Denitrification takes place in anaerobic areas like your deep sand bed and the inside of live rock, were oxygen levels are low and there is no light.

One thing is rinsing the bioballs with tank water, another very different think is completely cleaning them. If you rinse them (as in shaking them under water), you just remove the trapped debris and detritus (decaying stuff that causes nitrates to rise), if you scrub them...bye bye bacteria on that surface.

So you found one of the detritus traps now, the sponges (prefilters). Keep on eliminating the sources, and you will reach your goal [img]/ubb/smile.gif[/img]

Joaco


------------------
My webpage Updated 14th September 2000

I have a feeling your Dry-Lab test is inaccurate. I have 3 nitrate test kits. Red Sea Pharms and Fast-Test both show my 'trates to be less than 10 ppm. My Salifert test shows them at 25 ppm. I go with the latter. Altho not as precise as Hech or LaMotte, Salifert is in the upper end of accuracy.

I believe if your nitrates are really 140 your fish would not be feeling well at all. Sure, fish don't mind some nitrates, even up to 80 or so, but higher than that will effect them.

When I was having problems, one lfs tested my nitrates at 80. I was so upset I nearly came home in tears. All my fish were fine, and the snails, reef crabs and silver star fish were perfectly fine. I finally got the Salifert test, which showed 40 ppm. I decided to stick to that one and assume the test at the lfs showed a false high do to some organics or something. Anyway, I'd consider your 140 ppm a false high.

------------------
If it's broke, don't fix it---hide it.

You can clean the bio-balls till the cows come in, they will still produce nitrates!

Did a real clean up in the back of my uniquarium. Cleaned sponges, filter pads and did a 15% water change. To no avail, my nitrates still show 70ppm with salifest test kit [img]/ubb/frown.gif[/img]

2 days after a good clean up, sponges, filter pad and 1/3 bio-balls raised in saltwater my nitrates are down to 40ppm
[img]/ubb/smile.gif[/img] [img]/ubb/smile.gif[/img]

I also took other test,

SG 1.023
temp 78
Alka 10.6 dkh
Ca. 260ppm
Ammom 0
Nitrites 0
Nitrates 40ppm
Phosp. <.5

Since this is a FOWLR how important is it to keep ca. up?

Barry