Red Sea AB+ causing Diatom bloom?

[RichardinTN]

I’m currently experiencing a Diatom bloom (confirmed microscopically) in a tank that should not be having one (older, established) and I’m trying to chase down the Si source. RODI is coming out 0 tds and color changing resin is still good. The only thing I’ve been dosing more of recently has been the AB+. I’m going to stop it for a while to see if the population crashes but wondered if anyone else has had this happen.

 

[Gedxin]

What're your nutrient values? Did they go up after dosing AB+?

 

[blaxsun]

It’s honestly hard to say since I’ve got so much coralline over everything, but I probably does less than half of the recommended amount daily.

 

[RichardinTN]

What're your nutrient values? Did they go up after dosing AB+?

Phosphate has risen to .04 but nitrate is unchanged. Diatoms are driven by the presence of silicate.

 

[Roytrolls247]

Hate to say it but you may need an ICP test if you ruled out major elements and trace elements. Did you happen to add any dry rock recently?

 

[Randy Holmes-Farley Verified Community Expert]

IMO, if it really is diatoms, silicate in the RO/DI is likely.

Silicate is usually the limiting factor for diatoms in reef tanks.

 

[RichardinTN]

IMO, if it really is diatoms, silicate in the RO/DI is likely.

Silicate is usually the limiting factor for diatoms in reef tanks.

Absolutely sure it’s diatoms. I’m attaching a photo from the microscopic exam I did the other day. Dual TDS meters on my RODI are reading 0 and my color changing DI resin is not showing any change yet, not to mention it only having done perhaps 200 gallons of water. That’s why I’m scratching my head. I suppose it could be an issue with the resin but that just seems so unlikely. Nothing has been added to the tank as far as rock goes, only the increased supplementation of AB+. I have also bumped up my dosing of Red Sea Alk supplement but that’s only been a few ml per day. ‍

 

[Smite]

With 0 TDS from my RODI I still had detectable silicates in my water confirmed by a ATI ICP test. I added a SpectraPure HC silicabuster DI cartridge after my normal DI stage and my last results came back free of silicates.

 

[RichardinTN]

With 0 TDS from my RODI I still had detectable silicates in my water confirmed by a ATI ICP test. I added a SpectraPure HC silicabuster DI cartridge after my normal DI stage and my last results came back free of silicates.

I’ll have to look into one of those. Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Just adding a second normal DI cartridge may also work.

 

[Cjeippert]

With 0 TDS from my RODI I still had detectable silicates in my water confirmed by a ATI ICP test. I added a SpectraPure HC silicabuster DI cartridge after my normal DI stage and my last results came back free of silicates.

I had to do the same. 0 tds but a lot of silica still made it past my 2 brs di stages. The fix for me was switching to spectrapure silicabuster and max cap di. I Confirmed by multiple triton icp tests. In AZ we have very high silicates in our water and spectrapure is a local AZ company that makes great products. Not trying to knock brs, but their anion resin did not work well for me

 

[Cjeippert]

I had to do the same. 0 tds but a lot of silica still made it past my 2 brs di stages. The fix for me was switching to spectrapure silicabuster and max cap di. I Confirmed by multiple triton icp tests. In AZ we have very high silicates in our water and spectrapure is a local AZ company that makes great products. Not trying to knock brs, but their anion resin did not work well for me

A third di would be best for me, probably all anion media