Huge Diatom Problem HELP!

[mega]

My 80 gallon rimless has been running for about a year now, upgrade from previous tanks so sand and rock is all fully cycled. Only problem is all of a sudden im getting crazy diatoms.
I run my Radions a 65% for 6 hours a day, turned the green and red leds off to stop algae growth. Also when i do a 10-15 water change every week or two the diatoms are back within an hour and doesn't look like I did a water change or cleaned the sand at all. The sump is loaded with live rock in the fuge along with a DSB that never gets stirred up and lots of cheato. I have a tunze skimmer way overrated from the tank and a gfo reacto running as well. Anyone know what may be causing this problem?

Thanks for any help to come!!

 

[Randy Holmes-Farley Verified Community Expert]

What type of water are you using for top off and for water changes?

The thought is it may have substantial silicate in it.

 

[bairdimusprime]

I agree with Randy, what type of water are you using? if its a home RODI kit how often do you switch the membranes?

 

[mega]

It's rodi and every 3-4 months we switch out the same for top off is its rodi but here's the thing my other tabk has no diatoms in it at all and it's the same water

 

[Randy Holmes-Farley Verified Community Expert]

Are you monitoring the TDS of the effluent from the RO/DI?

 

[carolinareefguy]

Clean up crew

 

[mega]

Are you monitoring the TDS of the effluent from the RO/DI?

yes nothing is showing up

 

[mega]

Clean up crew

on that now!

Just added
5 spiral tops
2 turbos
8 nasarius snails for the sand

 

[Randy Holmes-Farley Verified Community Expert]

So the top off is 0 ppm TDS?

 

[Randy Holmes-Farley Verified Community Expert]

How do you know it is diatoms and not something else?

Cyano? Dino's?

 

[mega]

Because it's all brown and not red slime

 

[Randy Holmes-Farley Verified Community Expert]

OK, but dinos are brown and cyano can be brown too. I have some brown cyano, for example.

If it is not diatoms, then silicate removal is not going to be helpful.

 

[mega]

dont think its silicates because ive never had this problem untill i changed to led....

 

[Randy Holmes-Farley Verified Community Expert]

dont think its silicates because ive never had this problem untill i changed to led....

Not sure what you mean.

If they are diatoms, they need N, P, and silicate. If it is some other form of algae, it needs N and P, regardless of light.

But brighter light makes most pest algae grow faster.

 

[mega]

I still dont think its silicates because all the other tanks we have dont have that problem...any one chime in?

 

[Greg79]

Are they look like long brown algae with air bubbles trapped ?

 

[Greg79]

Any pics ?

 

[Greg79]

Are you running very low nutrient system ?

 

[DFW]

I still dont think its silicates because all the other tanks we have dont have that problem...any one chime in?

Did you use a different type of sand in this tank?

 

[Randy Holmes-Farley Verified Community Expert]

I still dont think its silicates because all the other tanks we have dont have that problem...any one chime in?

If it really is diatoms, them they must be getting silicate and other nutrients from somewhere. But if it is dino's or some other pest, then silicate is not needed.