dust algae

Hello everyone
This is my first post I have had a really hard time getting rid of this dust algae its so bad that within 2 hours of scraping the glass its green again.
Some tank info
125 gallon tank
110 pds live rock
2 250 metal halide
2 clown fish and a ton of coral
the only thing i changed was 2 weeks ago I replaced my sand bed bc it was 10 years old I am a total loss here its driving me crazy

 

Gonna need your water parameters. Mainly Nitrates and phosphates. You may have caused a mini cycle due to replacing your sand bed. Remember algae needs 2 main things to flourish. Light and nutrients. Are you running a skimmer?

 

nitrates are zero ph is 8.0 ammonia zero i dont know what my phos is I ran out of that test HAHA I am assuming it is high

 

High phosphates (po4) there's your answer Run some po4 remover via reactor or Chemipure Elite.

 

how old are your bulbs?

You already have algae so your phosphate test is going to read low because the algae is already eating it up. You may need some macro algae to compete or run a reactor.

 

Well lets look at the obvious guys. What did you replace your old sandbed with? I would would be willing to bet that you are having a good ole fashioned Diatom Bloom. Diatoms feed off of silicates and new rock and sand tend to be loaded with them. Scrape, scrape, scrape will be the best method of getting it off the glass. You could get a few more cleaner snails to help out or just wait about 2 weeks and they will die off naturally once they eat all the silicates.

 

I replaced the sand bed with crushed coral and a bag of live sand.
My lights have brand new bulbs as of last month MH with 10k bulbs
I actually just put 25 snails in today we will see what happens

 

I'm 99.9% sure it's the sand and crushed coral. With the amount that you had to put in a tank of that size it will take several weeks for the diatoms to eat everything. Just going to take time. A week or two more and it will probably start to fade. Keep us posted.