Could it be the Denitrate coil?

I have had issues with Nitrates since the tank was started. Now into month and the problem still exists. Could it be my denitrate coil? There was issues with it getting air into the system (due to not pay attention during water changes), and when I went to look at it yesterday there was no flow (was working a little over a week ago), and the lines were clogged. The water I did get out of the coil was full of junk, maybe some algae but small particles all the same. The coil was put in roughly when the tank was 2 months old. I got the plans from here on 3reef, I used the same on my old tank and worked great!

Tank Background:

55 DT, 30g sump/fuge DIY live rock used a couple of small peices (4lb max) of cure LR to try and seed DIY LR, sump/fuge had live sand added when system was started. 11 days ago I removed all the LR in the sump but what the mangroves were attached too. Also when taking out the LR I did remove a .5-1 in layer of algae, and added 20lb of more live sand ( hoping to add more bacteria). I had an algae problem for sometime but no longer see much of it. ( its was a loose floating algae light brown/green didnt make large colonies but did stick to everything)
The only things in the tank are small cerith snail, 5 conchs, maybe 15+ hermits, one small maroon clown, red spot blenny, and a fire shrimp. no corals
No I dont over feed and I wash the mystis shrimp before feeding, nor is it my test kits. I have had my LFS check it with their kits
I also started vodka dosing 11 days ago and have seen no decrease in nitrates
my params as of 11 days ago
pH 7.8
No3 50+
No4 1>
Am 1>
Alk 9.2
Mg 1300
Ca 500
SG 1.024

 

The question is with such a small fish load why are your nitrates so high and you need a coil.

How much DIY LR do you have? I wonder if your DIY LR has the porosity needed to support anerobic bacteria deeper in the rock.

Coils are fine and accomplish the same thing really, once you get them going and the colony stable. You could have killed it getting air into it. You don't want air.

Do you have enough flow through your rock to keep it clean? Take a powerhead and blast all your rock and see what comes out. LR in the sump is a waste trap. Keep as little as possible and keep the sump clean. The fuge can be as dirty as you like, but rock and rubble trap too much waste. You want the waste suspended so the skimmer can get it out.

So how is your skimmer working? Do you have any mechanical filters?


Wait a minute... You say your ammonia and nitrite are "1 greater than"??? Do you mean less than 1 or greater than 1? If you have any measurable ammonia or nitrites then you have a major problem with your biological filter. High nitrates being the least of your problems. It is possible you removed too much rock that was serving as your biological filter.

 

I was yhinking the same thing about removing the rock....it may have caused your nitrate spike

 

You see the nitrate level has been high from the start of the cycle. I have never seen them drop below 40. And the Nirtite Am. are below one. They have been at 0 most of the tank's life

As far as the rock is very porous, something I made sure when making the rock. And there is at least 80lbs of it. And I enough flow to keep debris off most the rock. (there is some caves and holes that dont get enough)

I did all my testing before pulling the rock work out. There was a lot of crap stuck in the rock, thus my reason for pulling it out.

I do have a skimmer and its is working well. As far as mechanical, I have a pad that I change every 12 hrs and use 3-5 days a week. I run it when ever anything gets stirred up.

I know how the coil works and I know air got in there, my thought was that while the coil was "recuring" it was putting more NO3 back into the system. (cause of the air). Also I think the because I didn't use enough bacteria for the large amount of rock its cause a huge delay in the colonies growth to this point.