If you read this thread, you would have known that the salifert silica test kit DOES NOT work.The Salifert test drawing a blank is puzzling:
1. Silicate to be dosed isn't what it claims to be?
2. Test kit is not working?
3. Type of Silicate isn't being detected?
4. Adding it to the tank causes it to immediately precipitate out?
5. Silicate binds to something immediately?
6. It's a freshwater and not saltwater test kit?
I'm going to try mixing RODI with known (probably) concentration high/low to test again.
Also mixed RODI and salt and repeating the test.
I'm also going to buy a bottle (not a LFS sample bottle) of the Silicate. Is Water Glass much more viscous than water? Perhaps I have was sold a placebo?
For now, with no way to dose and test I'm looking for guidance e.g. can you keep applying the recommended dosage of 2-4 ppm every few days? The Hanna Silicate Testers don't seem to be available to buy in UK - otherwise I would be tempted to get one.
Don‘t even worry about testing it. Just dose a known concentration once a week. That is plenty enough for diatoms and sponges.