question regarding skimming and nitrate, etc

[whosinpower]

Hi all;

I have a 90 gallon reef set up for about 6 weeks. It is new. I have about 90 lbs liverock, 2-3 inches sand, t-5 lighting, 4 powerheads, 2 tunze 6025's, and 2 koralia 2's. I have a sump and the return pump turns over about 5 times/hour. With powerheads, flow is about 30 times/hour.

I opted for a tunze doc 9010 skimmer and is skimming wet. Empty it every other day 400-500 ml.

Now, when I started, I had uncured liverock that gave me a robust cycle. Waterkeeper wisely advised me to do a big water change when my nitrites were really low, and nitrates were through the roof! At one point, they were off the scale, but seemed to be reducing and just before water change - nitrates were just over 50ppm. After waterchange, nitrates were around 20 ppm. One week later, I did a 15 gallon water change. Nitrates were less than 5 ppm.

I had assumed that hair algae, and macroalgae were taking up nitrates, reducing them. Waterkeeper again, advised that I get a cleanup crew to deal with the algae issue-which I did. They have been working really well, and my tank is looking pretty good. Rocks are developing a nice coraline covering, but still have green areas. Clean up crew is keeping hair algae well trimmed, and rocks do not have that fuzzy look.

Yesterday, I syphoned detritis off sand bed and did a 10 gallon water change. Had thought to do this as a weekly regimen. Just for interest, I tested nitrate to see where I was at. Nitrates are undetectable.

I know my sandbed is too new to convert nitrates. Where is it going? Is my skimmer taking out stuff before it gets converted? My rocks look green in some areas, but certainly not overgrown....clean up crew has taken care of the hair algae on the back glass - it is clean.

My newbie theory thought that nitrates would slowly increase if there was less algae present - and the clean up crew has made a significant difference.....but my theory kind of went out the window yesterday after I tested water.

I have three fish. 5 mexican turbo snails, 10 cerith snails, 5 nassarius snails and 1 emerald green crab. I have a few corals - 5 ricordea yumas, 1 green protopalythoa, 1 bright blue palythoa, a colony of bullseye mushrooms, a purple goniopora, a frag of gsp, a frag of galaxea coral, a rock of assorted zoa's and a frag of candycane coral. Lights are on for an 8 hour schedule - 6 hours are full lights, and 2 hours reduced lighting.
I feed the fish every day, and the corals are all target fed every other day with coral frenzy.

I'm certainly not complaining - just wanting to understand what is happening. Not planning on adding any more animals for another month.

Can anyone tell me where my nitrates went?

 

[PJSEA]

Live rock is the major component of the biological filtration system. The rock not only contains algae and photosynthetic corals but also has the bacteria to convert nitrate to nitrogen.

 

[plyr58]

Do you see gas bubbles on your live rock? This is bacteria converting the nitrate into nitrogen and it will exit your system. Are you doing anything in sump as far as manual removal of detritus (i.e. filter socks, etc)? This can removed biological water before it is ever broken down in the Cycle as well. finally, your protein skimmer is removing some of the waste as well. Count yourself lucky that you have no 'trate battle at the moment.

 

[whosinpower]

no filter sock - however, the fellow who made my sump had two seperate areas - one for mechanical filtration and one for chemical filtration that he built into the sump.

In the mechanical, I have a foam pad and filter floss on top - I change out the floss when I do a water change, and the foam is thoroughly rinsed/scrubbed in clean saltwater before going back in.The foampad can also be used if/when qt tank is set up.
Chemical filtration has a bag of carbon - this is changed every couple of weeks.

I blow off detritis off rock and sand every couple of days. Did this during cycle and have continued because rock was uncured and there was allot of crud flying off whenever I used a turkey baster on it. Water clears within a couple of hours of doing this.

I'll look closely tonight if I have bubbles escaping.

I do count myself very lucky so far. Just trying to figure out why.

 

[corals b 4 bills]

I recently removed my filter sock because it was making my nitrates go through the roof, so the foam pad and the canister filter will create the same problem, mark my words it may not look like a problem now (especially after "a good guy" made your sump installed this for you) but after a small amount of time you will have coral and or fish die-off, Gee I sound like a nay sayer but it's true maybe someone else can chime in here.

 

[Snausy]

Use the sock at the bottom of the overflow into sump when you do a "blow off" to collect all the crap when it comes down.... then remove it when the water starts clearing up. You can get rid of a ton of crap that way without leaving the sock in the sump to be a nitrate farm.

I did blow offs without one for a good while but got tired of my sump having so much crap on the bottom.

 

[mg426]

That is not a bad idea.