Diatoms, 2 months now

Ok my tank got the usual diatom outbreak ofter cycling, but it wont go away. It's been over 4 months. I was using tapwater and I know that is most of the problem, but I have switched to RO. I have done 2 12% water changes, but its still growing. How long till its starts to clear up? Is there another reason why the wont go away? My reading are ..
Amonia 0
Nitrites 0
Nitrates under 10

Any ideas or do I just need to wait for the RO water to start working?

Oh ya now I am starting to get some purple growth, I assume this is Cyano?

 

i would wait for RO to start working. do you have any fish in there yet? Also what are your lights?

 

I think the more appropiate phrasing would be wait for the tap water to stop working. the silicates using diatoms should disappear after the silicates are used up.

if its slimy and wipes of its cyano, if doesnt its coraline

 

Its a FO, I have a Osc. black and white clown, a Coral beauty, a yellow tail damsel, and a 3 striped damsel. I have 2 life glow t8's, 6,700k wich I just replaced last month.

 

the 6700K are GREAT for algae growth!

 

What size tank and what are our paramiters? What about ph kh salinty? calcium and mag? I had cyano for along time. 220 tank did not mature for over a year. red sea is still going after months.

 

Great, thats not what I wanted to hear. about the lights. Salinty is alittle high at .024, because my deepsix hydro is off, as I found out from some post on this forum this is common. Oh ya ph is 7.8

 

6500K is what most people use for their fuge, because its so good at growing algae... so, not that the lights are your only problem, they are not helping matters. If the bulbs are fairly new, i would try to return them, or sell them to someone with a planted FW tank. you dont have to buy a new fixture, but maybe changing the bulbs out would help. BUT, this is not your main problem.. just not helping.

 

Ok what type should I get without upgrading my fixtures?

 

Low PH and poor lighting added with tap water is probally the issue here. I would get better lighting up the Kh and ph to help with the algae. The salinity is fine at what you have..024 is nothing to worry about.