Silicate calculation for T. Weissflogii culture

[BitR0t]

Hi, trying to start a Thalassiora Weissflogii culture, but I am not sure how much silicate to add. I got the starter culture from reef legends, and they recommend 2ml/gallon of their 18% water glass solution.

I thought I would just use the Brightwell “SpongeExcel” product I have on hand. It states that 1ml will raise 1 gallon water by 4ppm of silicate.

Any idea how I can convert one of these into the other? Or if someone just knows a good dosing regimen of “SpongeExcel” in T. weissfloggi that works too lol.

My culture is 1/2 gallon.

Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

18% water glass has a density of about 1.15 g/mL.

2 mL thus weighs 2.3 g and since it is 18% water glass, it is about 18% SiO2 by weight, and it contains about 0.41 g SiO2.

If you put that into 2 gallons = 7.6 liters, the concentration is about 0.41g/7.6 L = 0.054 g/L or 54 mg/L = ppm.

You’d need 54/4 = about 14 times the Brightwell dose to match it.

 

[BitR0t]

Oh maybe I had just had an “oh duh” moment. 18% solution would just be 180,000 ppm, and the brightwell solution says minimum 15,000 ppm, so basically I need 12x more brightwell than the 18% stuff. I hope I’m not oversimplifying and forgetting about bonds or something… it’s been a minute since I did math with chemicals.

 

[BitR0t]

18% water glass has a density of about 1.15 g/mL.

2 mL thus weighs 2.3 g and since it is 18% water glass, it is about 18% SiO2 by weight, and it contains about 0.41 g SiO2.

If you put that into 2 gallons = 7.6 liters, the concentration is about 0.41g/7.6 L = 0.054 g/L or 54 mg/L = ppm.

You’d need 54/4 = about 14 times the Brightwell dose to match it.

Thank you for coming to my rescue @Randy Holmes-Farley

 

[Randy Holmes-Farley Verified Community Expert]

Thank you for coming to my rescue @Randy Holmes-Farley

You’re welcome.

Happy Reefing