Weird white stuff under rocks? Algae? Bacteria?

[imbob95]

Does anyone know what this weird white/clear stuff is? It’s almost like hair algae but it only grows on the underside of rocks. I’ve attached a gif and some photos (sorry about the in and out of focus and the six line he loves to be up in my business)

We’ve have a 13.5 fluval and have been having a few nutrient issues mainly keeping them at the right level

Nitrates have been as high as 20 ppm, but last time check were around 10ppm, but recently stuff is looking like it’s bottoming out a bit. We have a Hanna tester coming tomorrow for nitrates so have only been using API. We have barely any algae growth at the moment.

Phosphates 0.25ppm

We have a lot of zoas, a few lps, and a few sps

We dose iodine ~1ml every 4 days

3 fish and regular cuc and we feed mysis shrimp every day

We had something die a while back and so we had some carbon in the back, but it’s been in ever since — I read some bacteria eat this? Is it better to take it out if the tank doesn’t actively need it? We have a little bit of cyano but not a lot

Thanks for the help!

 

[slingfox]

Most people cannot view the video unless you post to something like YouTube. I can’t see the video but from your description it sounds like sponge. Sponge are harmless and generally a good sign.

 

[imbob95]

Most people cannot view the video unless you post to something like YouTube. I can’t see the video but from your description it sounds like sponge. Sponge are harmless and generally a good sign.

Oh shoot,

Here’s a gif and some stills— it doesn’t look like a sponge but the fact it’s under the rocks maybe?