Brand new to saltwater hobby

raduchief · Aug 26, 2019

Hi all! I am brand new to the saltwater hobby and have had a 75 gallon tank up and running for about 4 months. I cycled the tank with live sand and bio-spira. I haven't put any fish in the tank yet but have placed 2 frags:1)zoanthids 2 )what I think is a hairy mushroom ...both of which seem to be doing just fine.
My issue is what I think is an outbreak of diatoms, but hoping someone can confirm. It's on the rock and sand (see pic). I just added some cerith snails and a few Blue legged hermits to see if they would help with the algae. As well, I added a bag of chemi-pure blue for any issue with phosphates. Water parameters seem fine except phosphates which are .15 ppm hence the chemi-pure ...I read that u should have .1 or less but not sure... algae is very unsightly and I am wondering how to clear this up quickly. I have been told by LFS they most likely will just go away on there own but is there something I should be doing?

SoggyNW · Aug 26, 2019

Welcome to the site and the hobby! Am fairly new to this myself but that looks like the diatoms I had with my cycle.

How often are you doing water changes. And are you using RODI water or tap water? Which salt?

MTBake · Aug 26, 2019

Welcome to R2R

COreef8 · Aug 26, 2019

First of all, welcome to the hobby and R2R! It's an awesome and difficult hobby but you're starting off on the right foot here asking questions from the start.

That does indeed look like diatoms to me, and makes sense since it is a new tank. I wouldn't worry about it, it will go away on it's own after a while. It's part of what's called the "ugly phase". A new tank has new plastic, rock, and sand, all of which put silicon into the water, which is what diatoms feed on. Once they've consumed it, they will start to die off and water changes and filtration remove them from the water, it will clear up. You'll probably experience other types of algae too, like green/brown film algae and hair algae while the tank stabilizes.

My advice is try not to react to all these things because it can sometimes make it worse. Having said that, there are a few clean up crew critters that eat diatoms, my favorite being trochus snails. They're relatively cheap, hardy, hungry, and they can reproduce in your tank.

Phosphates at 0.15 is somewhat high, but again, I wouldn't worry about it too much in a new tank. It will likely stabilize lower if you keep up with maintenance and beneficial organisms grow.