New Tank - Algae or Diatoms?

XStroX

New member
My new 75 gallon acrylic tank has been cycled for about 3 weeks now. About a week ago I noticed a brown substance starting to form on the sand surface and rocks (see picture). I used RO/DI water and parameters are great and LFS recommended adding a clean-up crew. I am really hesitant on adding too many snails and all that as i don't want to end up with too many after they eat this algae. I also don't want to add crabs as I've heard many people recommend going without them. I purchased 8 snails (a mix of 4 different kinds, no Turbos) for $20 and put them in the tank yesterday. Obviously no difference today. Should I be buying tons more snails? With these small snails I feel like I would need 100! Should I be trying to stir up the sand or use a turkey baster on where it has built up on the rocks?

I don't want to wait until everything is completely brown...

Thanks.

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Diatoms usually hang around for a little while after the cycle. It should go away on its on since it doesn't have the large amount of nitrate to keep it going. Well that's if you did a good enough water change after the cycle.
 
So I used already cured live rock along with live sand in my RO/DI water. Because of that, I didn't seem to have a cycle. Ammonia, nitrate, nitrites all remained 0 for 8 days straight. At that point I started adding a few fish and some Xenia. Everything is doing fantastic. Xenia is taking off, fish look great and are eating great. Still 0 ammonia, nitrate and nitrite. Also 0 phosphate when I got it checked a couple days ago. This is based on LFS testing and my own.

So at what point do I do a water change based on that? I was going to wait until the 4 week mark.

Based on this though it seems like with 0 nitrate this diatom shouldn't last long.
 
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In my opinion, you have zoas and pallys that appear to be darn happy and brown stuff on the rocks. Frankly the tank looks pretty healthy, so I'd say increase your cleanup crew. The brown stuff is tasty, apparently, and snails will clean it up fast. Your long term goal is to slowly increase your imports and exports in order to have a healthy and colorful tank (assuming you are doing corals).

In my experience any new rock added to a tank, even an older tank, will go through the standard stages of brown, then some green, and finally coraline.

I would also get used to always posting all the important stats in any post asking questions. Just good practice and keeps you on top of your game.

Nitrate
Phosphate if you have a decent kit
KH
Calcium
Mag
Salinity

I would also start doing your regular water changes, there is NO reason not to do one.
 
Thank you both. I will do my first water change early next week. Just need to get a few tubs to make it easier.

As far as the rest of the parameters, here is where I'm at currently.

Ammonia = 0 (LFS verified)
Nitrate = 0
Nitrite = 0 (LFS verified)
pH = 8.2 (LFS verified)
Phosphate = 0 (from LFS)
KH = 10 (from LFS)
Calcium = 400 (from LFS)
Mag (I haven't asked for this yet)
Salinity = 1.23
 
Those are diatoms, phosphates and nitrates will feed it and cause it to spread more. Its a part of new tank syndrome. Nothing to worry about they will go away on its own.
 
Thank you again. I'll add a few more snails tomorrow. Although I may stay away from the turbo as I have read they knock rocks over and I'm slightly worried about my rock setup falling as of now. I'll probably go with an assortment of 8 more of everything but the Turbo. That and time sounds like will take care of my problem.
 
Nothing eats diatoms, it will go away on it's own like mine did. Turbos only eat the hair algae that grows on rocks anyway. I would get mexican turbo snails, they are a little smaller, mainly just so you don't get a hair algae problem later on as that is a pain to get rid of once it is in there...
 
Just be careful to not over do it with the CUC. I added two cerinths and 2 margarita snails that don't have much to eat anymore since I lowered my phosphates to near zero and my algae died off. Try to remove it physically first and if it comes back fast, then add a few more algae eaters.
 
Nothing eats diatoms, it will go away on it's own like mine did. Turbos only eat the hair algae that grows on rocks anyway. I would get mexican turbo snails, they are a little smaller, mainly just so you don't get a hair algae problem later on as that is a pain to get rid of once it is in there...

Kole yellow eye tangs love diatoms.
 
Kole yellow eye tangs love diatoms.

Really? I had a sailfin tang in my tank during a huge hair,cyano, and diatom outbreak and it only went for the hair algae.. the snails went for the glass :artist:.. and my floor... I even stepped on a few..:uhoh2:
 
Yeah, I had a kole that cleaned every single rock, the silicon & the power heads. Kinda felt bad when he finished them all because he never liked nori. Lost him in a temp malfunction :mad:
 
If you already have a cleanup crew. Do not add anymore. You will just be increasing your bioload and risk wasting money cause your cleanup crew will just die off, feed another bloom and you repeat a vicious cycle. If the bloom and algae problem does not dissipate after a few weeks, then add a few.
 
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