Controlling nitrates a problem. Please advise

[Kanejr10]

Hello everyone, I have been running a 36gal tank now for a year and I have always been battling nitrates. I assume some if it is probably overfeeding and little overstock. However I do 10 gallon water changes weekly to try to counter it. My nitrates are sky high not sure if it's a false reading or not using Api. I recently bought a rodi maker and tested my first batch of water all readings zero, ammonia, nitrite, and nitrates. Tds reading was also zero. I used that to make a new batch of water for a change. I did the change and tested water the next day the nitrates were down but still high as expected. Which hints that the Ali test is working. I have a HoB filter and I'm wondering if that could be the problem. It change the carbon frequently and rinse the sponge but i feel that the sponge could be the problem.

Currently in the tank is a cuc of a few hermits, two turbo snails, coral banded, and a conch. My fish are two osc. Clowns, firefish, bangaii, and a diamond goby. None of the fish seem stressed at all. I also have a good amount of hardy easy corals which are gsp,Xenia,zoas, mushrooms, open brains, frogspawn, green flower anenome and a large rbta. I have had most of the coral for 9+ months some longer except the rbta only been there for 2 months. Again all the corals are doing fine but slow growth. Which is why I'm not sure about my nitrate reading as nothing has died or lost color.

Any ideas for help would be appreciated, I'm going to bring a sample of water to my lfs tomorrow for nitrate test and see how it compares to mine but I think he uses api for it. My only thought is to remove the carbon and sponge from my hob and just use it as a flow source and maybe put chaeto or rock rubble inside? Also as a side note this might be important but I haven't had any algae problems, just small amounts here and there.

I do run a protein skimmer but it doesn't seem to really collect tons of stuff I have tried adjusting it many times but cannot seem to find the proper tuning or there just isn't enough stuff to skim out.

 

[Kanejr10]

I guess I should bring up that I'm almost at the point of trying to dose vinegar but I have read a ton on it and the results have been mixed, some say it's great others have problems. However if it is done correctly would be it beneficial for me? I just don't want to dose and then have a serious algae bloom.

 

[CStrickland]

Are we talking high like 12ppm or 120ppm?

 

[Kanejr10]

According to the test 80.

 

[CStrickland]

Yeah, that's high.
But I wouldn't do anything too drastic if all your stock is happy. Maybe just see what happens if you take the sponge out. Nitrates can take a long time to come down though.

Do you ever blow the detritus out of your rocks, or vacuum your sand?

 

[thelawnwrangler]

Yeah, that's high.
But I wouldn't do anything too drastic if all your stock is happy. Maybe just see what happens if you take the sponge out. Nitrates can take a long time to come down though.

Do you ever blow the detritus out of your rocks, or vacuum your sand?

Don't some say HOB filters need extra care in regards to nitrates?

 

[Kanejr10]

I vacuum the sand every other water change. Blast the rocks with a baster every week. I'm wondering if I should take a spare pump and get more flow behind the rocks? Think that would have any effect?

 

[thelawnwrangler]

how long have you had the RBTA? It looks good to me, but I am new as they come so wouldn't know

 

[Kanejr10]

@lawn, I have read some mixed reviews on hobs, some say they don't have any water quality issues and others say it's a nitrate factory, I would assume the factory would be the sponge that's why I'm thinking of tossing it. I do have a purigen inside as well.

 

[Kanejr10]

Rbta has been in there for two months and he has doubled in size.

 

[thelawnwrangler]

@lawn, I have read some mixed reviews on hobs, some say they don't have any water quality issues and others say it's a nitrate factory, I would assume the factory would be the sponge that's why I'm thinking of tossing it. I do have a purigen inside as well.

yeah I haven't had experience with one just read that. Do stuff get trapped inside? Your tank looks pretty nice to me so something is right.

 

[alexgv14]

Try adding a refugium with some cheato.

Also, try to get that protein skimmer working properly that will be a big help.

 

[CStrickland]

I vacuum the sand every other water change. Blast the rocks with a baster every week. I'm wondering if I should take a spare pump and get more flow behind the rocks? Think that would have any effect?

How much flow do you have now besides the filters? If there's not much water movement then your skimmer won't pull like you said. The filtration only cleans what it catches, so if food and poo just sink to the bottom that's bad. You need enough current to bring the dirty water to the filters.

Don't some say HOB filters need extra care in regards to nitrates?

Well, the sponge inside does. So it's pretty easy and low-risk to take out the sponge and see if they go down.

 

[Sk8r]

Vinegar is about the most benign and forgiving of carbon doses. GO by a chart. It WILL improve the output of your skimmer considerably.

 

[Kanejr10]

It's a sumpless system so I basically have no room for anything else, the skimmer is a hob as well which is part of the reason it can't skim all that well. I have hydor pump on the opposite side of the tank from the filter flow. I cannot remember the size but it's a pretty big one. It's on the left glass blowing towards the front middle.

 

[Kanejr10]

I do have a smaller pump that I'm thinking of putting on the right side to blow behind the rocks which would be the direction to where the skimmer pump is as well which could help with the skimming?

 

[CStrickland]

Might help.
Also, what's your feeding schedule? How much/ how often?

 

[Kanejr10]

I have also been debating reaquascaping to allow more flow between the rocks, however I fear causing a mini cycle and upsetting my rbta he likes his spot and if I rescape he could likely move and kill all of my other corals.

 

[Kanejr10]

I used to feed what would be about 3/4 of a cube of Mysis a day in two feeding but have cut back to about a half a cube maybe less in one feeding. I should say that the diamond goby is a fatty and eats a ton of it not much is left over for the cuc

 

[CStrickland]

I wouldn't call that over feeding at all.
Rescaping get might do more harm than good. I had a fit last month and rearranged stuff, my nitrates went through the roof, never had an issue before That's the sort of drastic thing I'd only do as a last resort.