Chaeto melting

[Gtinnel]

About 6 or so months ago I decided to add a small ball of chaeto to my sumps refugium section. I didn’t really need it for nutrient export but I figured it would allow me to feed even more and the added night time pH boost was a plus. It has grown great up until a few weeks ago, when I noticed it was starting to disintegrate. I know that is usually blamed on lack of trace elements when that happens, often iron. I checked my last icp test and at the time my chaeto was growing and iron was undetectable, and since then I have actually increased my dosage of tropic Marin A and K trace elements because I had several trace elements that were undetectable. If I’m dosing more then I wouldn’t think trace elements would be the problem. I am planning on sending in an ICP but until then any suggestions on what to try. My nitrates are starting to raise a little higher than I want, and I assume it is the chaeto releasing nitrate back into the water.
The only thing I can think of that I changed when it started to disintegrate is that I started dosing Acropower, although I doubt that is related. I actually assumed the Acropower was increasing my nitrates but now I suspect it was the chaeto.

 

[T-J]

What's your phosphate level?
Are you skimming as well? There may not be enough nutrients to support it.

 

[Gtinnel]

I just checked a few hours ago and my phosphates are at .08 and pretty consistently stay between .05-.1. My nitrates that usully stay in the 5-10 range recently have gone up to 14. Not an urgent level but higher than I’d like. I’m also starting to see some undesirable algea in the tank.
Yes I do run a skimmer but I’ve never bothered to try and adjust it to get the best possible performance out of it. I used it for pH increase and oxygenation more than I needed it for nutrient export.