The use of Sodium Silicate And Sodium Metasilicate

[JulesH]

Randy,

I have an dinoflagellate issue in my tank, its has been ongoing for a few months now. I know what particular dino it is, but all my efforts to rebalance my system to reduce the population of dinos has not worked so far.

I have read your article on 'Silicates in the reef aquariums' and I was thinking to try and dose Sodium Silicate to promote diatoms. I have found a local source (here in the UK) of liquid glass, a 40% solution. Then I find Brightwell offer SpongeExcel using Sodium metasilicate (at twice the price).

I have had a rummage through the web trying to find the differences between Sodium Silicate and Sodium Metasilicate, from a general use there are distinct differences.

My question from a reef tank perspective to promote diatoms, which solution would be best with minimal adverse effects please?

Many thanks for taking the time to read this.

Julian

 

[taricha]

There's not much difference in the silicate and metasilicate for our purposes in a reef tank.
Brightwell is low concentration and has dosing calculations on the bottle to help you target a particular concentration.
waterglass is very high concentration and Randy provides the calculations to target a certain concentration.
I used spongexcel until I got used to how my tank processed Si, then I switched to a cheaper higher concentration product more similar to water glass.

 

[Shigshwa]

Randy,

I have an dinoflagellate issue in my tank, its has been ongoing for a few months now. I know what particular dino it is, but all my efforts to rebalance my system to reduce the population of dinos has not worked so far.

I have read your article on 'Silicates in the reef aquariums' and I was thinking to try and dose Sodium Silicate to promote diatoms. I have found a local source (here in the UK) of liquid glass, a 40% solution. Then I find Brightwell offer SpongeExcel using Sodium metasilicate (at twice the price).

I have had a rummage through the web trying to find the differences between Sodium Silicate and Sodium Metasilicate, from a general use there are distinct differences.

My question from a reef tank perspective to promote diatoms, which solution would be best with minimal adverse effects please?

Many thanks for taking the time to read this.

Julian

What is your reason for increasing the diatoms in the tank?

 

[Randy Holmes-Farley]

Generally, when folks have dinos, the thought is that diatoms outcompete the dinos for the same physical space on rocks and such, and are much less problematic growing there.

 

[JulesH]

What is your reason for increasing the diatoms in the tank?

They supposedly out-compete the dinos and are easier to reduce when the dino problem has been overcome?

 

[Randy Holmes-Farley]

They supposedly out-compete the dinos and are easier to reduce when the dino problem has been overcome?

I personally see no reason to try to reduce them, but if you stop dosing silicate they will not keep growing.

FWIW, I regularly dosed silicate to supply sponges and other organisms that use it, and the diatom effect was never any problem. The glass actually was easier to see through when diatoms grew on it than when green algae did. I discuss these issues here:

Silica In Reef Aquariums

Why would I recommend dosing silica? Largely because creatures in our tanks use it, the concentrations in our tanks (at least in mine) are below natural levels, and the sponges, mollusks, and diatoms may not be getting enough to thrive.

reefs.com

 

[JulesH]

Thanks for getting back. I read your article thats what gave me the idea of dosing silicates, thanks Randy.

 

[Randy Holmes-Farley]

Thanks for getting back. I read your article thats what gave me the idea of dosing silicates, thanks Randy.

You're welcome.

Happy Reefing.

 

[JulesH]

Randy,

I have read your article on reefs.com about Silica in reef aquariums. I have been trying to figure out my dosing to get to 1ppm of SiO2 in my 300 litre reef tank.

I have a silicate solution 41° Baume and have been using the equation below to try and work out what 0.5ml of the solution would be in ppm if I dosed it to my tank?

I am using the equation:

Concentration (ppm) = (Mass of solute (in grams) / Volume of solution (in litres)) × 10^(6)

However I am getting the answer of 1,300,000 ppm?

I have gone wrong and I dont see my error and would be very much obliged for your thoughts.

 

[Randy Holmes-Farley]

dosing is far from critical, but do you intend to measure it out by weight or volume? It is fairly dense so there’s a substantial difference.

 

[JulesH]

Whatever is easier wrt to weight or volume.

 

[Randy Holmes-Farley]

From my article:

A concentration of 41° Baume equates to 29% SiO2 by weight. Note that the density is high (1.38 g/mL for 41° Baume),

Thus 1 mL contains 400 mg of SiO2 equivalents.

To add 1 ppm = 1 mg/L to 300 liters, you need 300 mg, or 0.75 mL.

 

[JulesH]

From my article:

A concentration of 41° Baume equates to 29% SiO2 by weight. Note that the density is high (1.38 g/mL for 41° Baume),

Thus 1 mL contains 400 mg of SiO2 equivalents.

To add 1 ppm = 1 mg/L to 300 liters, you need 300 mg, or 0.75 mL.

Doh! Thanks Randy.

 

[Randy Holmes-Farley]

You're welcome.

Happy reefing.

 

[JulesH]

Crikey I see what you mean about this liquid, it is harsh and it takes some water movement for it to be absorbed.

 

[Waldek M.]

From my article:

A concentration of 41° Baume equates to 29% SiO2 by weight. Note that the density is high (1.38 g/mL for 41° Baume),

Thus 1 mL contains 400 mg of SiO2 equivalents.

To add 1 ppm = 1 mg/L to 300 liters, you need 300 mg, or 0.75 mL.

When water glass dissolves, a large amount of magnesium particles precipitate. Should it be filtered before pouring into the aquarium or should it be poured into the roller mat chamber so that the particles remain on the filter fabric?

 

[Randy Holmes-Farley]

When water glass dissolves, a large amount of magnesium particles precipitate. Should it be filtered before pouring into the aquarium or should it be poured into the roller mat chamber so that the particles remain on the filter fabric?

You should not have particles before adding to the tank, and the particles formed in the tank will redissolve and should not be removed.

 

[Waldek M.]

You should not have particles before adding to the tank, and the particles formed in the tank will redissolve and should not be removed.

Can I pour it into the sump, roller mat as a preventive measure, or does it have to be poured directly into the aquarium?

 

[Steve2020]

I just ran across this thread and I don't mean to highjack it but if worried about precipitate why don't you just add the silicate to some RODI water then add it to the tank? If I remember correctly when I asked a question about dosing silicate many moons ago, @Randy Holmes-Farley gave me the recommendation to add my dose of Loudwolf 41% Sodium Silicate to some RODI and then add that to the tank. I get ZERO precipitate doing it this way. Sorry @Randy Holmes-Farley if I mistakenly said it was your recommendation but I think it was you.

 

[Waldek M.]

I just ran across this thread and I don't mean to highjack it but if worried about precipitate why don't you just add the silicate to some RODI water then add it to the tank? If I remember correctly when I asked a question about dosing silicate many moons ago, @Randy Holmes-Farley gave me the recommendation to add my dose of Loudwolf 41% Sodium Silicate to some RODI and then add that to the tank. I get ZERO precipitate doing it this way. Sorry @Randy Holmes-Farley if I mistakenly said it was your recommendation but I think it was you.

When poured into the aquarium, the rodi mixture will not precipitate anything?