Please help me figure this out!

[Captain Jack]

I just recently set up my first reef aquarium. I put 2 clown fish, a yellow tank and two crabs in the tank about 1 month ago. about 3 days ago I ordered 8 frags online and put them in my tank after acclimating them and dipping them in Coral RX. I am now getting dark brown spots all over the sand and all over my live rock? Not sure if this is a kind of algae or something? I have a 40 watt UV sterilizer, BRS media reactor that I run carbon and GFO in and a oversized protein skimmer. I just tested the water and here is what the parameters are: PH= 8.0; KH = 1.8; Nitrate = looks like 20 but could be higher--the color is hard to get the exact reading; Ammonia = 0-0.1; Calcium = 480--assuming you also include the initial liquid you use for the titration? MG = 1,400 assuming you add the .4 ml for the titration. I use a Red Sea test kit. I plan on doing a large water change tomorrow and maybe one on Monday or Tuesday.

The fish and the Coral all look really healthy. I just want to figure this out before it gets bad.

Thanks for any suggestions!

 

[Broadfield]

Sounds like diatoms.... they feed on silicates. It's typically a brown "dust" that forms on the sand, glass and rocks. If it is indeed diatoms, then it will eventually go away... it's just part of a new reef tank cycle. Silicates are typically introduced by your new sand. Once the silicates are all used up by the diatoms, then it will fade away as fast as it appeared. A detailed, large and close-up image would help identify your brown stuff.

 

[nervousmonkey]

+1 to Toby. It's diatoms, and they'll go away on their own but it'll look ugly. You will have to blast the rocks and sand and suction as many out as possible. What is your phosphate level? Since you're running GFO I assume low, but you never know. An alternative to waiting it out is Phosguard. It very very quickly removes phosphates *and* silicates, which is what is feeding your diatoms. Get a bottle of it from PetCo, I think PetSmart would have it, or order it on Amazon (at that point, might as well wait it out). If you can get Phosguard tomorrow and put it in with your carbon in the reactor, or put in that thing "The Bag" from SeaChem and drop it in your filter sock, or an area of high flow, and then stir up your sandbed really well a couple times a day, enough to cause the water to become cloudy, and let the overflow take it down to your filter sock or reactor, it'll pull out the silicates, which will eliminate the source of food for the diatoms.

As as aside, did you rinse your sand super well, as in rinsing it over and over until it's clear? That always helps get a lot of the silicates out. My method is to put the sand in a 5 gallon bucket, put it in the bathtub under the spigot and turn on the water, stirring the sand around with your hand, or an instrument. Keep doing this until water runs clear (it will take some time). Then pour out as much of the water as you can, keeping the sand out of the tub (unless you really like your wife to yell very loudly at you), then pour all of the sand into another bucket and start the process over. I do this back and forth for a good 45 minutes to an hour, and haven't had a diatom bloom in years when setting up a new tank. I also use PhosGuard though for the first few days, so that contributes a lot to removal of silicates.

Good luck! If you see more and more brown appearing, it's definitely diatoms.

 

[JaimeAdams]

If the spots aren't moving I agree with Broadfield. If the spots are moving around it could be flat worms coming in on the live rock if you used it. Chances are it's just diatom growth.

 

[Captain Jack]

That makes sense. I forgot to mention that about 3 days ago I purchased 6 lbs of refugium mud from BRS. My sump is below my tank and my fuge is in the sump. It is a small ruge--only like 8 inches wide and the water flow goes right through it. My tank got really cloudy for a few hours after adding the fuge mud, but then it settled and there were no spots. A couple days later the spots appeared, so that makes perfect sense that it is from the silicates. I will take a turkey baster and try to blast the spots off the liverock, if it doesn't go away in a few days on its own.

Thanks for the help guys!