Diatoms or something else...?

[george9]

Hi everyone...I know there are lots and lots of posts like these but I have seen very little pictures of algae that looks similar to what I am seeing. My tank has only been set up just about a month at this point so I was assuming any areas of brown growth I was seeing would be diatoms. The tank was cycled using Biospira and pure ammonia, I added a few easy soft corals about two weeks ago after I was processing about 2-3 PPM of ammonia in 24 hours. I have no livestock yet other than the corals, so my bioload is low. I did water changes after the cycle to get the nitrates down to 20PPM, and then I added a bit of chaeto into the back chamber to further reduce. Nitrates are currently between 0-5 PPM and phosphates are near .25PPM on the API test.

I started getting some brown growth on the sand about two weeks ago and assumed this was diatoms. More recently, I am seeing brown stringy algae growth on the glass and back wall of the tank. It also has started growing on some of the frag plugs and has really ticked my zoas off. I'm blowing off and removing the strings, but on the frag of zoas it keeps coming back and is preventing a few polyps from opening. It takes some effort to remove as well, not quite powdery and easy to remove like diatoms usually are. It's on the upper portion of the rocks as well, but there are no bubbles on any of the strings. The entire top portion of the sandbed is a bit 'sticky' and clumpy, but not all areas are brown.

I noticed the past couple days that my filter floss turns brown QUICK. Like within hours I'll see a brown tinge and within 24 hours it needs to be changed, even though the water is clear. The water also has a little bit of a fishy smell despite no livestock. I blew a ton of it off my GSP and now it's been closed for a couple days. The corals just seem a bit off and not as happy the past few days - but could be from me forcibly cleaning them off lol.

I've attached some pics...I definitely think some of it is diatoms but the stringy nature of it seems a bit weird.

Thanks for any advice!

 

[george9]

Here are some pics:

 

[george9]

Here is another picture showing how it’s growing on the glass. Powdery in some areas (diatoms likely) but there’s also brown “filaments” blowing with the current hanging onto the glass as well. Almost like what would pop out of a blackhead you pop on your face haha.
Same thing is growing at the top of my rock work where flow + lighting is maximized (not sure if they like the high flow or high lighting but I’d assume it’s the latter)

has anyone seen this before?

 

[TheSharksDen]

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