major green dust algea and diatom problem

[Beepster1353]

ok so i had a 75 gallon saltwater fowler set up for 2 years with no algea problems. a month ago upgraded to a new 90 gallon. i put all the old sand underneith some new argonite sand to create a dsb, and added all my old live rock. i also saved about 70 gallons from the old tank and filled the new thank up with that, plus natural ocean water bought from the pet store. ive been topping off with distilled water bought from the store. im now a month later having to use a magnet cleaner twice a day to get the green dust algea off the glass. my 6 lamp t5 tek light setup is only a month and a half old, with all new bulbs. and there only on for 6 hours. i have the deltec mce 600 skimmer, and the fluval fx5 canister filter that i change regulary. also no outside light is getting to the tank. this algea is freaking me out making me think i might have to rip everything out and start over. i only have four fish, some snails, crabs, sand sifting sea star, and a urchin. please help me..

[ecvernon]

I think you should start by testing your water parameters. For the algae problem start by testing P04, Nitrate , nitrite. without knowing your numbers my first thought is that it may have to do with your previous FOWLR . in that system you may have built up phosphate and nitrates in your rock and live sand bed now it is are leaching back out.

a simple fix may be running a Phosphate reactor, but you can be sure when you start your testing.

[thegrun]

+1, water parameters would help. I suspect that you are seeing the results of covering your old sand with several inches on new sand. Since the organisms that were living in your old shallow sand bed were used to getting oxygen and are now in an anaerobic environment they are dying off and are the source of the nitrates feeding the algae.

[Beepster1353]

Thats what i was afraid of. Should i ride it out or take out all the sand and start over??

[Mavrk]

Originally Posted by Beepster1353

i put all the old sand underneith some new argonite sand to create a dsb

I suspect this is the problem. How much sand did you add on top? Your old sand had living things in there. If you covered it too much, then it would become anaerobic (as you want with a DSB) and you would have a good amount of die off. Definitely check your parameters.

[coralsnaked]

If you saturate a living sandbed with an overlay, the result is a new N cycle and the rise in same. What comes next? Should be a rise in amonia levels. Be prepared for lots of water changes. Watch your crabs, if they start to go then your fish are already on the way. A rule of thumb is NEVER mess with a sandbed. And if you feel you must, then never more than one inch a week in either direction deeper or thinner!
Lessons learned

[Beepster1353]

i figured out that i messed up by putting the new sand on top about two days after the fact..i added about 3 inches to the 2 inches of old stuff. whooops. so in your guys opinions, should i rip all the sand out, and start over?? or ride it out, doing regular water changes and lots of testing?? all my perams are up, but not high enough to hurt anything. my nitrate is about .25 and my ammonia is just above 0. also my phospates are reading 0. it just sucks seeing something i worked so hard on get screwed up because i messed up and put the old sand underneith. so far my crabs are good, and my sea urchin is doing good also.

[andy2966]

I am pretty new to the forum. But maybe you could mix the old sand and the new sand together. Just a guess. But I would try mixing the sand up as best I could.

[Beepster1353]

anybody? should i take the sand out or ride it out?

[rbirling]

I vote keep an eye on the parameters and do water changes and/or amquel plus as needed. If you stir it up more you'll likely make things worse. Just my opinion.