High Nitrates on established tank

[Newsmyrna80]

I noticed last week that my frog spawn wasn't extending like it normally does. So I checked parameters and all was within range with the exception of nitrates which read 40 ppm.
I have an 80 gallon with a 30 gallon refugium. I estimate with all the live rock and sand I probably have about 80 gallons of water. I've done three water changes (2 15 gallon and 1 30 gallon) in the last week and they still read 40. I added purigen but that did nothing. I'm at a loss at to what to do.
I've checked my RO water and the nitrates were at 0.
I've had a reef tank for 15 years. About 8 years ago I did upgrade my tank and moved some of the sand and live rock to the new tank. Could the nitrates spiking be old tank syndrome?
I've thought about carbon dosing but if there is a better way of reducing nitrates I'd rather do that given I've read bad things can happen with carbon dosing.
Any advice is welcome! Thank you!

 

[Tcook]

Do you ever clean/vacuum the sand bed? How deep is it?

Sent from my SM-G965U using Tapatalk

 

[Sk8r]

Cleaning the sump, if it's collecting stuff, would help. You might need a better skimmer, depending on what you have. Consider refreshing the CUC and maybe feeding a little less for a while. All suggestions in additon to those above.

 

[bertoni]

I would try running a nitrite test. Nitrite will confuse nitrate test kits. That problem is very rare, but it's annoying to discover that you're trying to solve the wrong problem.

Assuming the nitrite level is zero, I agree that the problem might be organic debris buildup, either in the sump or refugium, or the sand. Coarse sand is more prone to this problem, and crushed coral is terrible, in my experience.

For the time being, since a coral seems to be having trouble, I'd stop feeding for a bit. If there's no debris issue, you might need to consider carbon dosing or adding more live rock to the system.

 

[Newsmyrna80]

I vacuum the sand with every water change. It's maybe 2-3" deep in some places. My refugium does have a dsb but I've never vacuumed that.

 

[Newsmyrna80]

Cleaning the sump, if it's collecting stuff, would help. You might need a better skimmer, depending on what you have. Consider refreshing the CUC and maybe feeding a little less for a while. All suggestions in additon to those above.

I did take out some filter pads that I had in the refugium in the event I had to seed an emergency tank or something. I have a CUC in quarantine right now. I don't want to put them in right now because of the nitrates. I did cut back severely on the feeding and my foxface is not happy with me:lolspin:
I have the correct size skimmer for my tank but I HATE it! It will be running fine then it'll overflow everything right back in the the refugium (of course when I'm not home). So I'll have to unplug it until I have time to mess with it and it could stay off for a day or so. I don't remember the name of it but I got it at Marine Depot and it gets good reviews...not from me though.
So I'm off to do research on a GOOD skimmer

 

[Newsmyrna80]

Thank you Bertoni..I'll do a nitrite test. Should I replace my sand? I've read that in an old tank the sand will need to be replaced or removed all together (which I'd rather not do due to the livestock).
Shouldn't I have seen some changes in the nitrate results given I did such large water changes?

 

[Michael Hoaster]

What's going on in your 30 gallon refugium? Get it well-lit and put some macro algae in there. I recommend a combination of fast-growing greens and slower growing reds. Ulva and Grasilaria are two good examples.

 

[Sk8r]

As for skimmers, I have an Eshopps that's performed well. Needs some maintenance right now but that's after years of service, and I haven't angsted over it because I'm cultivating shrooms right now. It did bust my own nitrate problem.

 

[Newsmyrna80]

Really!! It helped with the nitrate problem? Thank you for the recommendation

 

[Newsmyrna80]

What's going on in your 30 gallon refugium? Get it well-lit and put some macro algae in there. I recommend a combination of fast-growing greens and slower growing reds. Ulva and Grasilaria are two good examples.

The dsb in the refugium has never been vacuumed so I'll try that next. I do have chaeto in there and a light, but it's not the best light. I have a ton of chaeto in my QT but I have a CUC team in there so I will have to wait til the quarantine time is up, which is next week.

 

[bertoni]

Nitrate levels can bounce back up rapidly, so depending on how long you waited before measuring, the water changes might not have much effect. You could try a 30% change and then measure immediately. If that doesn't help for a bit, then there might be a test kit problem.

I don't know how coarse the sand in your tank is, but anything above the finest grade can trap a fair amount of debris, and then need changing. Personally, I'd consider this after trying some other measures.

Anything where debris builds up or is filtered aerobically can produce nitrate in the water column. That includes artificial bio-media, like bio-balls and the like.

 

[Newsmyrna80]

Nitrate levels can bounce back up rapidly, so depending on how long you waited before measuring, the water changes might not have much effect. You could try a 30% change and then measure immediately. If that doesn't help for a bit, then there might be a test kit problem.

I don't know how coarse the sand in your tank is, but anything above the finest grade can trap a fair amount of debris, and then need changing. Personally, I'd consider this after trying some other measures.

Anything where debris builds up or is filtered aerobically can produce nitrate in the water column. That includes artificial bio-media, like bio-balls and the like.

I waited about 20 minutes to retest. I've ordered a Salifert test kit but it hasn't arrived yet (no LFS carry them). The sand is not very coarse (it's Aragonite) and I've been vacuuming it. I did recently get a tiger pistol and he has dug a lot under the live rock that has been there for years. I'm wondering if that hasn't released nitrates in to the water column. I've never used bio-balls as I read they did contribute to increase in nitrates. I just have filter floss in there but it gets changed weekly.
I believe that my skimmer is a big problem. I've been having problems with it for years. It's a Skimz and I hate it. I'm researching a good skimmer that'll fit in to my refugium. I'm currently looking at an Aquamaxx ConeS.
Thank you for your advice Bertoni!

 

[bertoni]

You're welcome. I agree that a good skimmer is an excellent investment. The digging by the tiger pistol shrimp could be part of the problem, too.

 

[Newsmyrna80]

You're welcome. I agree that a good skimmer is an excellent investment. The digging by the tiger pistol shrimp could be part of the problem, too.

Ugh dang shrimp I'm researching skimmers now and poised to do another water change. Thank you all for your help!

 

[bertoni]

You are welcome. Good luck!

 

[Newsmyrna80]

Thank you�� Retested yesterday and nitrates were down to 20. I did another water change after that. Maybe the water changes, aggressively vacuuming the sand and cutting back on feeding is working���� I also tested nitrites in the event that was affecting the nitrate readings..they were 0.

 

[Sk8r]

If you do go for another skimmer, get one that produces whipped-cream-like foam, not one that just bubbles. My own rule of thumb is get a skimmer rated higher than your tank size. Double is not too much.

 

[Newsmyrna80]

If you do go for another skimmer, get one that produces whipped-cream-like foam, not one that just bubbles. My own rule of thumb is get a skimmer rated higher than your tank size. Double is not too much.

Thanks Sk8r, any recommendations for a skimmer? I have an 80 gallon w/ a 30 gal refugium. I was looking at a Red Sea RSK300. Thank you