Chaeto dying in Refugio’s

[reefer1]

Looking for some help. Thanks!
About 4 weeks ago I built a new sump and added a refugium. The tank water drains into a chamber where I have some slots cut to divert some flow to the refugium. Most of the flow goes to through a vertical baffle to the slimmer, some live rock, and return pump.
I also decided to try not using a filter sock. I added a large ball of chaeto and set up a kessil H80 tuna flora a few inches above the water line. PAR is about 150 midway below surface.
I have noticed the chaeto slowly shrinking. Today I pulled what was left and it was covered in a black film. Plus the bottom of the refugium has detritus.
Lastly, NO3 has been slowly rising from about 2ppm up to about 10ppm. All other tank parameters are dialed in.
Any ideas what killed the chaeto?

 

[Flippers4pups]

One of two things. One lack of nutrients or light.

N03 rise is most likely from the chaetomorpha dieing off


Edit: or contaminants in water.

 

[rkpetersen]

Looks like maybe a microalgae or even bacteria growing on it. Although that could just be secondary to the chaeto starting to die off.

I've had chaeto collapse mysteriously before as well. Light, nutrients, flow all adequate, and yet the chaeto would just suddenly lose color and disintegrate into short grayish strings. And also while the chaeto in a virtually identical setup in a different tank sump is thriving. I suspect there are other factors at work in some cases of chaeto collapse, either some element in the water that the chaeto is concentrating that harms it, or some microorganism attacking it, possibly even a virus.

One thing you might do if you're not doing it already is to start supplementing small quantities of iron. Chaeto seems to like it.

 

[Flippers4pups]

Looks like maybe a microalgae or even bacteria growing on it. Although that could just be secondary to the chaeto starting to die off.

I've had chaeto collapse mysteriously before as well. Light, nutrients, flow all adequate, and yet the chaeto would just suddenly lose color and disintegrate into short grayish strings. And also while the chaeto in a virtually identical setup in a different tank sump is thriving. I suspect there are other factors at work in some cases of chaeto collapse, either some element in the water that the chaeto is concentrating that harms it, or some microorganism attacking it, possibly even a virus.

One thing you might do if you're not doing it already is to start supplementing small quantities of iron. Chaeto seems to like it.

Yes lack of iron can contribute to paling and dissolving.

 

[reefer1]

I have never dosed iron. What product do you recommend?
I see Brigthwell Aquatics offers Ferrion Liquid Salt Water Conditioner and another product Chaeto GRO Algae Fertilizer

 

[smiley28]

https://www.bulkreefsupply.com/lugol-s-solution-advanced-iodine-brightwell-aquatics.html

 

[rkpetersen]

I have never dosed iron. What product do you recommend?
I see Brigthwell Aquatics offers Ferrion Liquid Salt Water Conditioner and another product Chaeto GRO Algae Fertilizer

I use Ferrion. (I also use Lugol's as above, but that's iodine, not iron. )

 

[JumboShrimp]

Should the flow in the refugium be light, medium, or heavy for best results with chaeto growth? Thanks...

 

[smiley28]

I use Ferrion. (I also use Lugol's as above, but that's iodine, not iron. )

No clue why but my mind jumped to iodine/lugols