The silicate battle

[wackyreefer]

So I have recently been battling what I believe is diatoms. Didn't take long for me realise that one of my problems was that I had zero nitrate and phosphate.
I sorted that out by dosing both however, my diatoms didn't go away as expected.
I then proceed to test my tank water for silicate (Salifert Silicate test). Test came back zero. (no surprise there considering the diatoms!)
I then decided to test my RO/DI water and guess what 0.25ppm silicate...

So did my usual reef2reef reading and most suggestions were to either a) Add a silicate buster cartridge to your RO/DI system b) Add a second DI stage to your RO/DI system.
Had a look around locally for silicate buster but this is not available locally.
I then decided to try out Plan B and buy a second housing and cartridge to try the second DI stage option. At the same time I swapped out my sediment filter for good measure two.
Ran it for some time to settle in and again tested for silicate (direct from output - not from RO/DI container), guess what 0.25ppm :mad:

So why am I posting this you might ask, I already have the most documented solutions? Well I guess I am interested to hear from other people on:

1. Is 0.25ppm silicate really a problem or am I looking in the wrong place and my diatom problem is actually for a different reason?
2. Is 0 ppm silicate a must have? I read somewhere that Randy actually doses silicate from time to time for his sponges...
3. If 0 ppm silicate is a must have, is SilicateBuster the only way forward without putting GFO in the tank which would also deplete phosphate (which in my case is already very low)?

Thanks ;Bookworm

 

[Randy Holmes-Farley Verified Community Expert]

You sure it is diatoms and not dinos?

Low nutrients usually skew the problems toward dinos.

 

[wackyreefer]

You sure it is diatoms and not dinos?

Low nutrients usually skew the problems toward dinos.

Hi Randy

So my understanding/definition of diatoms are brown, dusty, easy to blow off into water column with turkey baster. Dino's also brownish but more stringly/slimmey and produces bubbles when the light are on.

My issue is definitely the former unless my undeserving and identification is wrong?

Thanks

 

[wackyreefer]

H

You sure it is diatoms and not dinos?

Low nutrients usually skew the problems toward dinos.

Hi Randy

I guess the thing I am trying to figure out is 1) Is finding silicate in ro/di water unnusual? 2) if not is 0.25ppm very bad?

Thanks

 

[Randy Holmes-Farley Verified Community Expert]

0.26 ppm SiO2 in top off is not bad if you are not suffering from excessive diatoms. If you use that for top off, it is less than I dosed.

SIlicate is one of the harder things to bind in a DI and it is often added to tap water by water companies, and is also often present naturally. Can be 5 ppm in tap water.

 

[wackyreefer]

0.26 ppm SiO2 in top off is not bad if you are not suffering from excessive diatoms. If you use that for top off, it is less than I dosed.

SIlicate is one of the harder things to bind in a DI and it is often added to tap water by water companies, and is also often present naturally. Can be 5 ppm in tap water.

Thanks very much Randy.
I guess this is nudging me in the direction of perhaps my identification of diatoms vs dino's is the problem. Perhaps it's a less severe case of dino's that I am dealing with.
I will try and keep my nitrates and phosphates up and see if that solves the problem.

Thanks again.