Phytoplankton dosing causing diatoms

[djf91]

So I’ve been dosing phytoplankton for the past couple of months to outcompete Dino’s and feed microfauna/coral in my system. The Dino’s are 99% gone now after looking under a microscope. What is present under the microscope is diatoms. Multiple species of diatoms it appears. And they now populate my sand bed much like you would see Dino’s do.

Im suspecting that the phytoplankton im culturing and dosing is contributing to this sand bed diatom bloom, probly because of excess silica in the culture being dosed. I stopped dosing phyto yesterday to see if the diatoms disappear.

Has anybody experienced this before? Is there a culture medium for phyto that doesn’t contain silica? Would the phyto (Nanno) grow without a silica component? Im using Guillards f/2 from Mercer of Montana.

 

[blaxsun]

Sounds like you might need some sand cleaning crew (conches, cerith snails, nassarius snails, possibly a black sea cucumber).

 

[fullinfusion]

Im dosing Ocean Magic and haven't had any of those issues, but im not looking under a microscope. At the least Im seeing better conditions and they seem to be doing there job. I do however have a good CUC going and good flow in the DT. I'm interested on what others say so I'll be watching this thread.

 

[reef_1]

Has anybody experienced this before? Is there a culture medium for phyto that doesn’t contain silica? Would the phyto (Nanno) grow without a silica component?

Yes. You can do the recipe without sodium silicates.

Or what I did is that I simply used liquid plant fertilizer, 2 quid per 1L, the greens grow in that one very well (I havent dosed that in my tank though - used the phyto for zooplankton only).

 

[djf91]

Yes. You can do the recipe without sodium silicates.

Or what I did is that I simply used liquid plant fertilizer, 2 quid per 1L, the greens grow in that one very well (I havent dosed that in my tank though - used the phyto for zooplankton only).

What brand did you use? Any risk of heavy metals?

 

[reef_1]

What brand did you use? Any risk of heavy metals?

Don't remember, used random ones off the shelves in the garden centre which had a good ratio of phosphate and nitrates.

There is definitely a risk of unwanted stuff, but I didnt dose phyto directly to the tank, I only used it to feed rotifers and pods.

But it will happily grow in it.