just a supplement - no actual algae contained in the bottle.
i've read a few people mentioning that it wouldn't be a good thing to add to a tank w/ filter feeders due to the particulate size, but i had made use of it prior to reading this...didn't notice any ill effects. just something to potentially throw a little research towards if you are considering using it.
at least judging from my experience, it does promote coraline growth (no other supplementation done for the above tank as of the taking of that picture), but no, there isn't any coraline 'seed' in the bottle, just the stuff to promote it's growth.
I happened to get some as an exchange for some snails that died in route by dhl shipping. The livestock company and I had no idea that the cargo hold of the truck was not heated and they were all dead before I got them. They credited my account for the cost of the snails and to make the story short one of the things I got with the credit was purple up.
Its probably best to use it in conjunction with a calcium test kit.
Just another product to take your money. Coraline will come in time providing you have good lighting and your Ca & Alk are in check. Randy just wrote a post about this product, short but sweet. Don't waste your money on this product, IMO.
check drs foster and smith or marinedepot. C-balance and B ionic have been recommended to me--gobyjohn above says B ionic has iodide---I'm not sure about C-balance--not specifically listed on their advertisements.