Last chemistry problem

Actuarial Goat

New member
Been up for about 8 weeks, here's my numbers:
pH 8.2
sal 1.026
temp 82
Ca 580
alk 12dkH
phosphate nil
nitrite & amm nil
nitrate ~50ppm

So of course the last one is my final concern before I start adding corals. It's a 44gal corner tank. Right now there's 60 pounds LR, 5" sand (mixed some live and dry aragonite), a 24" CPR AquaFuge with a huge clump of green macro, Remora Pro, and few powerheads. 250W 14K MH lamp. The only life I've added is a small pair of false percs and an orange diamond goby. The fish seem quite happy.

The question is regarding the nitrate. The article I read from Randy says I'm using all of the preferred methods (fuge with macro, DSB, skimming). Am I just being impatient? Does it take longer for these methods to "kick in" and begin eliminating nitrate? I will do water changes, but even a 50% water change only gets me to 25ppm, and I'd like to get below 5, eventually down to 0.

Also, if anyone cares to comment on my high Ca, feel free. I don't supplement (yet), so I'm figuring it came from my salt mix (SeaChem ReefSalt) and from brand new aragonite, and from the fact that there's little to no demand for Ca in the tank right now.

Anyway, please comment on the nitrate. Thanks.


New member
every tank is different, and distinctives of your system may be such that it's taking that long. sounds like you're doing all the right things. I'd continue to do water changes and wait it out. 50ppm of nitrates will not be good for the corals. how long have the fish been in? their waste and the additional organics [left over food, etc.] may contribute to bigger bacteria populations and begin dealing with your nitrate. how long since nitrites spiked, at what level, and when did nitrates first become detectable?


NTTH Rookie Help
Premium Member
theres no magnesium reading, and your calcium is high, try testing for mag, you may be suprised at the result


ReefKeeping Mag staff
Premium Member
I battle nitrates in my system which has a well fed poulation of fish.I am running over 30ppm with heavy wet skimming, a 30g remote dsb and 80 gallons of chaetomorpha. I run gfo and carbon as well. Phosphates are under control at consistently less than .1ppm. Of course lots of live rock. I think I still need more macroalgae refugia on the 575 g system. BTW the nitrates are not adversely affecting my corals in a discernable way.(lps/sps) and there is very little nuisance algae. . I am in the process of cycling a diy sulfur denitrator to add to the mix, since I would like to get them under 20ppm preferably around 10 ppm. Some are reporting very good success with these devices.

If you are not getting abiotic precipiotation of calcium carbonate( white stony buildup on heaters , powerheads and other heat sources) I wouldn't worry about the calcium at 580ppm.


In Memoriam
How are you testing your Salinity & PH ?

I agree with TMZ the nitrates can be a real challenge. There are no instant miracle cures for nitrates, it takes some real effort on your part to keep nitrates in line.

Actuarial Goat

New member
Thanks everyone. The live rock was out of water a total of 25 minutes, so very little die-off led to no detectable cycle. The spike happened after I added the percs, which was 5 weeks ago. It only lasted 3 days, and I'm guessing from the two tests I ran that it probably peaked between 1 and 2ppm. Nitrates followed three days later and have slowly grown since. I must admit I didn't test at all between weeks 4 and 6.

I understand the high calcium can cause precip, but does it harm the organisms? I did have a considerable build-up on the powerheads around week 2, but I wiped them down, and it's gone now.

The high nitrate is contributing to a brown algae problem.

Salinity is via the floating glass-tube type. I tried a refractometer but apparently I'm an idiot because it doesn't seem to do anything....need to take it back and ask them to show me how to use it or else replace it. pH is via Salifert and cross-tested against API. It has been very consistent at 8.2.

I need to get a Mg test kit, haven't been able to yet.

I realize that nitrates require some real effort, but I guess what I'm asking is what other effort can I give it? Could it just be a patience issue, or do I need to actively make a change? For what it's worth, I think I feed very sparingly, so far either one very small pinch of flake or half a cube of frozen mysis every day, only one total feeding per day.


ReefKeeping Mag staff
Premium Member
Nitrates. The only suggestions I can make are; remove detritus buildup frequently. Puff it up or suck it out with a turkey baster. Blow off the rocks too. Thaw and rinse the mysis before feeding. The packing water is nutrient laden. Harvest the chaeto once a week or so. Give it room to grow. Check out the monster diy sufur denitrator thread on the diy forum. Skim wet and run carbon. Extra live rock could also help.if you are useing any mechanical filtration keep it clean. If you are using high oxygen areas with media , rubble or bioballs consider slowly removing them.

Calcium at 580ppm or even higher will not harm the organisms in your tank. The high calcium,however, may cause precipitation of calcium carbonate particularly if your ph gets high(8.6 or so) which may decrease alalinity more significantly than the calcium. Lowered alkalinity can be harmful to corals and other organisms. For every 20ppm of calcium taken up as calcium carbonate 1 meq/l (2.8 dkh) of alakalinity is used. Magnesium discourages precipitation and assists in maintaining high calcium levels So if your alkalinity is ok and ph is ok , high calcium is not harmful. FWIW,my numbers are; Calcium 580ppm,alkalinity 11.6 dkh, magnesium 1450ppm sg 1.026, ph 8,25 daily low/8.35 daily high.


New member
When I first setup my 90g, it took about 6 weeks for my nitrates to come down to zero. Are you seeing growth in your macroalgae? I think as long as your macro is growing, the tide will slowly turn.

A couple months ago, a nitrate problem "crept up" on me. :) I stopped testing my nitrates regularly as it was always zero. Well, I noticed some of my SPS polyps weren't extending as well as they used to, so I did a complete water test. My nitrates were in the 40 range. I realized that the reflector on my fuge light had dulled due to salt creep and significantly slowed down the growth of my macro. I did a couple 50% water changes, but even with that, it still took about a month for my nitrates to come down to zero.

So as long as you're seeing growth in your macro, I'd just be patient!


ReefKeeping Mag staff
Premium Member
Macro growth will reduce nitrates but for many it's not enough unless you have quite a lot of it.