Dosing silicates

Rakie · Mar 30, 2019

Last follow up question -- How much to dose?

I had followed your suggestion at 1mL/200mL RODI. But I was wondering if there's a certain amount I should be aiming for or something like that.

jedimasterben · Mar 31, 2019

Rakie said:
Last follow up question -- How much to dose?

I had followed your suggestion at 1mL/200mL RODI. But I was wondering if there's a certain amount I should be aiming for or something like that.

There really isn't any hard data to go on. I'd keep doing what you're doing for a few weeks and see if anything changes.

Enigma84 · Dec 16, 2019

Did anybody get to the bottom of the dosage? I have just bought a 500ml bottle of 40% sodium silicate. I'm hoping to just dose a small amount to encourage the diatoms to grow enough to strangle out the Dino's. I have a 165 gallon. Any scientists looking can suggest a starting dosage of the 40%?

ReefLab · Apr 7, 2020

Enigma84 said:
Did anybody get to the bottom of the dosage? I have just bought a 500ml bottle of 40% sodium silicate. I'm hoping to just dose a small amount to encourage the diatoms to grow enough to strangle out the Dino's. I have a 165 gallon. Any scientists looking can suggest a starting dosage of the 40%?

Ill bring back this thread since I just did the math anyway. You need to dilute the solution.

if you dissolve 12.5g of 40% Na2SiO3, in 400mL of RODI water, 1mL of that solution will contain about 8mg of SiO3. Use that to achieve the desired level in your tank. (1ppm=1mg/L)

For example if you have a 400L tank, 50mL will contain 400mg SiO3, raising the level by 1ppm.

Let me know if you'd like me to expand on the calculation.

KenO · Jun 4, 2020

ReefLab said:
Ill bring back this thread since I just did the math anyway. You need to dilute the solution.

if you dissolve 12.5g of 40% Na2SiO3, in 400mL of RODI water, 1mL of that solution will contain about 8mg of SiO3. Use that to achieve the desired level in your tank. (1ppm=1mg/L)

For example if you have a 400L tank, 50mL will contain 400mg SiO3, raising the level by 1ppm.

Let me know if you'd like me to expand on the calculation.

Can you make the solution stronger? I have a 600 gallon setup. Using your math above I would have to dose around 284ml. If I was to dissolve 50grams of 40% liquid glass in 400ml of RO/DI water it would be at a 4x concentration vs your example. So I would dose 71ml of the solution. Would that work?

Randy Holmes-Farley · Jun 4, 2020

KenO said:
Can you make the solution stronger? I have a 600 gallon setup. Using your math above I would have to dose around 284ml. If I was to dissolve 50grams of 40% liquid glass in 400ml of RO/DI water it would be at a 4x concentration vs your example. So I would dose 71ml of the solution. Would that work?

I dosed commercial water glass directly to my sump.

KenO · Jun 4, 2020

Randy Holmes-Farley said:
I dosed commercial water glass directly to my sump.

Ok. How about I start with the standard 40% first lol. If I want to raise the level in by 1ppm in 600 gallons as stated above, is my math correct?

Randy Holmes-Farley · Jun 5, 2020

KenO said:
Ok. How about I start with the standard 40% first lol. If I want to raise the level in by 1ppm in 600 gallons as stated above, is my math correct?

To be precise (which is not at all needed) you do need to measure 50 grams that you mention, not 50 mL (which you didn't suggest, but some folks might think to do).

40% sodium silicate (not 40% silica; not sure which you meant) weighs a lot more than 1 gram per mL, so 40% has more than 40 grams of sodium silicate in 100 mL of solution. Probably closer to 56 grams.

If you add 50 grams of 40% to 400 mL (final concentration is about 20 grams per 435 mL (46 mg/mL) and then dose 71 mL of that solution (3266 mg sodium silicate) to 600 gallons (2271 L), the sodium silicate dosed is 1.4 mg/L. Of that, about half of that weight is "SiO2", so about 0.7 ppm SiO2 equivalents.

Fortunately, dose is very noncritical. If you dose X amount, in a few days, you might be at less than a quarter that amount left.

KenO · Jun 5, 2020

Randy Holmes-Farley said:
To be precise (which is not at all needed) you do need to measure 50 grams that you mention, not 50 mL (which you didn't suggest, but some folks might think to do).

40% sodium silicate (not 40% silica; not sure which you meant) weighs a lot more than 1 gram per mL, so 40% has more than 40 grams of sodium silicate in 100 mL of solution. Probably closer to 56 grams.

If you add 50 grams of 40% to 400 mL (final concentration is about 20 grams per 435 mL (46 mg/mL) and then dose 71 mL of that solution (3266 mg sodium silicate) to 600 gallons (2271 L), the sodium silicate dosed is 1.4 mg/L. Of that, about half of that weight is "SiO2", so about 0.7 ppm SiO2 equivalents.

Fortunately, dose is very noncritical. If you dose X amount, in a few days, you might be at less than a quarter that amount left.

Thanks Randy!

joaocdestro · Apr 12, 2021

Hello Guys, I'm confused by the measurements, I need your help.

I have an aquarium of 935 liters, and I purchased this Sodium Silicate 40-50% (SiO2 27,5-29,5%), how much ml dose per week?

Molecular formula: Na2O (SiO2) n (2 <n <4)
Molecular weight: -xChemical composition: The chemical composition of sodium silicate is usually expressed by
weight or molecular relationship between silicon and sodium oxides. So a sodium silicate
ratio 3.3 parts by weight of silicon oxide (SiO2) to 1.0 parts by weight of silicon oxide
sodium (Na2O). Commercial sodium silicate solutions can range from 1.6 to 3.98 parts
by weight of SiO2 to Na2O.
UN No
CAS: 1344-09-8
Na2O: 8.40 to 9.20%
SiO2: 27.5 to 29.5%
SiO2 / Na2O ratio (w / w): 3.00 to 3.35
Baby (at 20 oC): 39.00 to 41.50
Specific weight: 1.360 to 1.420 g / cm3
Viscosity at 25 ° C: 70 to 170 cp

______________

Backgound:

I have Dino's Amphidinium - Then I dosed No3 + Po4 - It recuced but still on sandbed.
1. NO3 1-4PPM / PO4 0,04-0,08
I have GHA - Then I used API Algaefix + (fluconazole - used once a week 5mg per liter for 3 consecutive weeks, brushed all stones, but I still have it on my reef, I could not get rid of it)
NOW my sandbed are full of Cyano + a little of dinoflagelates...
I purchased a microscope and I have no signs of Diatoms, I just have Ciano + Dino.

My hope is to dose silicate asking for Diatoms help... what do you think?

KenO · Apr 12, 2021

First of all, I would say slow down on all the chemicals. I've found for cyano that balancing the NO3 to PO4 ratio helped me. It took several weeks for it to disappear. Look at the redfield ratio. I don't shoot for exact numbers but try to keep it within a range.

For the silicate mixing and dosing here is what Randy HF told me sometime back. I have a 600 gallon setup. Just adjust the amount to dose based on your setup.

Sodium silicate

To be precise (which is not at all needed) you do need to measure 50 grams that you mention, not 50 mL (which you didn't suggest, but some folks might think to do).

40% sodium silicate (not 40% silica; not sure which you meant) weighs a lot more than 1 gram per mL, so 40% has more than 40 grams of sodium silicate in 100 mL of solution. Probably closer to 56 grams.

If you add 50 grams of 40% to 400 mL (final concentration is about 20 grams per 435 mL (46 mg/mL) and then dose 71 mL of that solution (3266 mg sodium silicate) to 600 gallons (2271 L), the sodium silicate dosed is 1.4 mg/L. Of that, about half of that weight is "SiO2", so about 0.7 ppm SiO2 equivalents.

Fortunately, dose is very noncritical. If you dose X amount, in a few days, you might be at less than a quarter that amount left.

Randy Holmes-Farley · Apr 12, 2021

joaocdestro said:
Hello Guys, I'm confused by the measurements, I need your help.

I have an aquarium of 935 liters, and I purchased this Sodium Silicate 40-50% (SiO2 27,5-29,5%), how much ml dose per week?

Molecular formula: Na2O (SiO2) n (2 <n <4)
Molecular weight: -xChemical composition: The chemical composition of sodium silicate is usually expressed by
weight or molecular relationship between silicon and sodium oxides. So a sodium silicate
ratio 3.3 parts by weight of silicon oxide (SiO2) to 1.0 parts by weight of silicon oxide
sodium (Na2O). Commercial sodium silicate solutions can range from 1.6 to 3.98 parts
by weight of SiO2 to Na2O.
UN No
CAS: 1344-09-8
Na2O: 8.40 to 9.20%
SiO2: 27.5 to 29.5%
SiO2 / Na2O ratio (w / w): 3.00 to 3.35
Baby (at 20 oC): 39.00 to 41.50
Specific weight: 1.360 to 1.420 g / cm3
Viscosity at 25 ° C: 70 to 170 cp

______________

Backgound:

I have Dino's Amphidinium - Then I dosed No3 + Po4 - It recuced but still on sandbed.

NO3 1-4PPM / PO4 0,04-0,08

I have GHA - Then I used API Algaefix + (fluconazole - used once a week 5mg per liter for 3 consecutive weeks, brushed all stones, but I still have it on my reef, I could not get rid of it)

NOW my sandbed are full of Cyano + a little of dinoflagelates...

I purchased a microscope and I have no signs of Diatoms, I just have Ciano + Dino.

My hope is to dose silicate asking for Diatoms help... what do you think?

I do not know if dinos will be impacted here, but trying is not a problem.

I'd dose 2 mL twice a week. Exact dose is not critical, as mentioned above.

schuby · May 21, 2021

Randy Holmes-Farley said:
I do not know if dinos will be impacted here, but trying is not a problem.

I'd dose 2 mL twice a week. Exact dose is not critical, as mentioned above.

Is it OK to use a plastic syringe to dose 40% Sodium Silicate solution directly to high-flow area in sump/tank?

Randy Holmes-Farley · May 21, 2021

schuby said:
Is it OK to use a plastic syringe to dose 40% Sodium Silicate solution directly to high-flow area in sump/tank?

Do you know the type of plastic?

schuby · May 21, 2021

Randy Holmes-Farley said:
Do you know the type of plastic?

No. I have several of the 1mL plastic syringes that come with Hanna checkers and reagent refills. I also have a free, 10mL plastic syringe from Target pharmacy. I'd prefer to use one of the 1mL syringes because I've read that Sodium Silicate is hard to rinse off and I regularly use the 10mL syringe for my weekly water param testing.

Randy Holmes-Farley · May 21, 2021

I personally just poured a little into the cap from the bottle, and poured the capful into a high flow area of the sump.

The syringes are likely oK It is just that polycarbonate will be damaged by the high pH over time. Other likely materials are fine.

FBAA · May 21, 2021

Won't silicates generate diatoms? The brown stage of a new tank.

schuby · May 21, 2021

FBAA said:
Won't silicates generate diatoms? The brown stage of a new tank.

Not necessarily if you have something else that outcompetes them for the Silicate. Sponges will do that and I consider them extremely beneficial to my tank.

Randy Holmes-Farley · May 21, 2021

FBAA said:
Won't silicates generate diatoms? The brown stage of a new tank.

Yes. Not a problem in most established tanks.

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