New diatom outbreak?
 

Two weeks ago I switched from a Solaris light to an Outer Orbit with mh and t5's. A few days later I started getting some diatoms. Now, I have a pretty bad outbreak. Dark rust color on sand and some rock and I have to clean the glass 2 or 3 times a day. I didn't have any diatoms when I set the tank up 3 months ago with the solaris. The only thing new that went in the tank at that time was the sand, everything else was transfered over from my 65 and 90. Could the lights be causing this outbreak? And what can I do? Just wait it out? Also, it seemed to really take off after a dose of flatworm exit. I did 3 - 40 gallon water changes from Thursday to Sunday.

it could be your water.... do you use tap?? or do you use ro/di ? If you use ro/di do you get it from your LFS? " local fish store" it could be that there ro/di filter needs a tune up .. Check your alkalinity and ph levels ... and anything that has silicates, don't use.

Diatoms thrive on silicates, along with lighting. Sand frequently is the way the silicates get into a marine system. I'm not sure I understand when the sand went into your system but that's probably the source. Even disrupting sand can definitely release silicates and trigger a diatom profusion. Most likely, it will decline in a fairly short time on its own. If you really object to it and want to be proactive, get some reactors and use a good quality phosphate-removing medium...like Rowaphos, or something similar...they also remove silicates.

I use ro/di, my water is 0 tds from the filter. The sand is araganite sand. I took the live rock from the othe 2 tanks but used all new sand instead of trying to recycle what I had. I do have 2 phosban reactors running carbon right now. They are both running carbon because of the flatworm exit. I'll switch one back to phosban.

[QUOTE][i]<a href=showthread.php?s=&postid=11545905#post11545905 target=_blank>Originally posted</a> by sgarron [/i]
[B]I...used all new sand instead of trying to recycle what I had. I do have 2 phosban reactors running carbon right now. They are both running carbon because of the flatworm exit. I'll switch one back to phosban. [/B][/QUOTE]

Using new sand, then is no doubt, the explanation for the diatom outbreak. It will almost certainly take its course and abate on its own after some time. Most likely, the change to having phosban in the reactors will move it along eventually.