When you say you'd use an already made solution that is readily available.IMO, I'd use an already made solution that is readily available, but the material you have will work.
1 ppm silica (not 1 ppm Si) is already quite high. 1 ppm Si is higher still. I recommend dosing to 200 ug/L silica (SiO2).
That said, you can determine what dose you need by trial and error.
If you want to boost SI to 1 ppm SI, then you need 750 mg in your system.
The material you have is 10% Si by weight, so yes, you need about 7.5 grams of that material.
Trying to get 7.5 grams of the solid to dissolve in 5 mL of water seems a crazy high concentration and may not work out.
I'd experiment a few times to see what you are able to attain (regardless of published solubility).
First, I'd try dissolving the 7.5 grams in 25 mL of water. if that works for you, I'd use a stock like that.
Dosing the highest concentration possible is NOT desirable. You are more likely to cause precipitation problems. It may be better to dissolve it in even more water, even if it does all dissolve in 25 mL.
1. Like SpongExcel?
2. Why do you recommend this over DIY, is the price similar? I recently noticed your DIY for phosphate was 100x cheaper. Do we not see big benefit with DIY Silica
Thanks Randy, you rock!

