John . Good luck with them.
As we discussed, after 18 good months , I'm sticking with vodka and vinegar for now. At least I know the end product is acetate which is beleived to be somewhat useful to corals. I don't know what effect long term use of the pellets and the ploymers may have. Although the manufacturer's claim the carbon source is not miscible( does not diffuse through the water) like directly dosed carbon sources , I'm skeptical of the claim that the organic carbon source in the pellets is wholly consumed on the surface of the pellet and won't move into the water column.
There are many posts on the various threads citing the appearance of stringy white material and bacterial blooms which mirror problems which sometimes occur with overdosing of other carbon sources that are dosed directly into the water( vodka, vinegar, absorbic acid, glucose, etc.). if the organic carbon source stayed on the on the pellets throughout the bacterial activity, then what's feeding bacterial blooms in the tank?
Several things I would do if I were starting carbon dosing ie solid via pellets or otherwise:
Get your nitrates down under 10ppm via other methods
( reduced feeding, gac, heavy skimming water changes ,denitrators, etc) before starting. Carbon sources seem to work better at reducing initial lower initial level and then holding them down. Blooms and difficulties show up in reports whne the process is initiated with lots of pellets in high NO3 tanks. IME the nitrates wouldn't move off the 50ppm mark temptin me to dose more. I didn't. Once I knocked them down with a sulfur denitrator moderate carbon dosing has held them near zero.
Second ,I'd introduce the pellets over a period of time ,starting with a small amount and working up solwly while observing for any adverse reactions.
Third, test for PO4 and NO3 frequently to monitor progress and to determine how much product to use.
Fourth , make sure your organic carbon export system is up to snuff.Heavy skimming , gac, etc.
Good luck and keep us posted.
