High nitrates and dying chaeto

[Bronzebackhuntr]

So, I’ve had my tank up for over a year. I’ve been fighting high nitrates (like 50+) for over a year. What’s weird is that I’ve had no fish problems, no algae problems, and no coral problems. Set up a new sump/refugium with marine pure blocks and chaeto, but my chaeto is dying off. With my nitrate levels being what they are that chaeto should be growing like a weed, but it’s getting soft and falling apart. Any ideas? I’m at a loss....

 

[EmdeReef]

So, I’ve had my tank up for over a year. I’ve been fighting high nitrates (like 50+) for over a year. What’s weird is that I’ve had no fish problems, no algae problems, and no coral problems. Set up a new sump/refugium with marine pure blocks and chaeto, but my chaeto is dying off. With my nitrate levels being what they are that chaeto should be growing like a weed, but it’s getting soft and falling apart. Any ideas? I’m at a loss....

Cheato can be very finicky. It needs potassium, iron, manganese etc. you should try Ulva, much easier and faster to grow IME.

 

[rkpetersen]

You definitely need to have adequate trace elements, especially iron, and adequate flow over and through the chaeto, to keep it healthy.
It also needs phosphate to grow; if you have high nitrate but low phosphate, it'll grow until the phosphate is used up, and then crash.
I'm not personally fond of ulva. I've tried it, and found it would easily spread to the DT and was inclined to grow on powerheads, gyres, etc. Also hard to completely remove.

 

[Dan_P]

What is your PO4 level?

 

[jwshiver]

How are you lighting your cheato?

 

[IslandLifeReef]

Like @Dan_P said, what is your PO4? Without any, or very low PO4, you are being limited by the least available nutrient. Think of it as the weakest link. Without PO4 which chaeto needs to grow, it won't consume NO3 either. Thus, you get high NO3 readings and the chaeto slowly starves and dies.

Are you using anything to remove PO4 other than chaeto, such as GFO?