I was really expecting it to be a silica based product.
I did too, I was quite surprised that I
measured no Si.
But 1 drop per 100 Liters would be a very tiny amount of Si, even if it were concentrated waterglass (and it's not - smells strongly like acetic acid.)
....or maybe the acetic acid is screwing with the test
It was a quick look, I didn't eliminate the possibility of interference.
Just a follow-up, spongepower (my bottle from 2020) doesn't add detectable Fe or interfere with the Fe test, even at 100X recommended dose.
I used the hanna low range Fe checker to measure tank water, and added a dose of Red sea Trace C "Iron+" that should result in 100 ppb Fe. This data is in Blue below and shows the expected result. Undetectable in tank water, and near ~100ppb after addition of the red sea Fe product.
Then I did the same thing but with 1 drop / Liter of SpongePower (100x dose), shown in Red.
It neither added Fe nor interfered with the detected Fe from the Red Sea Iron+ product.
my bottle is from 2020 like I said. Since they list no ingredients, I suppose that makes it easy to change them any time you want
The guy I got it from may have sent me the wrong test results but I doubt it.
This "placebo" works as my tank is now loaded with sponges.
Again - to be clear, I'm not saying my quick look is definitive that the ICP results are wrong. Just that it should be double-checked first, to see if there is in fact significant Fe and Mn in a dose. Before we take those results as fact and spend much time thinking about how Fe and Mn dosing helps sponges.
(I used it too, and felt like it maybe helped sponge growth. I stopped when I realized I had no idea what was in it, and the things actually needed for sponge growth I can provide through known ingredients. )