I hope I can get in online this week!
A few pages back I wrote about the test I started with a relatively new product from Tropic Marin, " Reef Actif". Basically it is a slow working carbon-source additive, based on marine bio-polymers.
After some weeks of testing, I can say I saw some significant changes. The algae film on the bottom of the tank has almost completely disappeared, and the glass also don't need as much cleaning as before. Also the water became more clear.
Skimmate production has almost doubled. Basically I have noticed all the symptoms of carbon dosage. Increased skimmer activity, less nutrients/algae, clear water etc.
The only difference with for example Vodka dosing was the darker and richer colors I noticed in my SPS, instead of increasing pale colors. This can be the result of the increase of bacterioplancton in the water feeding the corals, and/or the carbon source directly feeding the zooxanthellae. The same darkening is noticed when dosing large carbon containing molecules like sucrose. (table sugar)
Smaller molecules like Ethanol seem to have a lightening effect on SPS, and larger molecules like Vinegar, Sucrose and Reef-Actif a darkening effect.
My experiences with this product are positive and I will continue to use it, combined with additional carbon dosing and addition of bacteria by Prodibio (BioDigest).
I'm also looking what the long-term changes for my sponges will be.
Leonardo