The only reason some folks have a problem with their tank not cycling immediately with B-S is because it was not kept refrigerated properly from manufacturer to your tank. There is really no way to be sure of that, unless you buy from a place like Drs Foster & Smith. I was at a LFS & they had a bottle on their counter. They insisted it didn't need refrigeration. I told them to read the label. After being on their counter for 2 months, they put it in the fridge for sale for the next unfortunate customer to buy. A friend was at the wholesalers & saw a skid with cases of B-S sitting in their heated warehouse!
If kept properly refrigerated, B-S should instantly cycle a tank, as long as you add the fish immediately. No ammonia/nitrite/nitrate spike or anything. If added into an uncycled/crashed tank after fish are in there though, it may take up to 48 hours to eat up the ammonia/nitrites that were already present. And never use in this case, without a large WC beforehand. Especially if you used any kind of ammonia-removing product. That will definately cause the new bacteria to starve & die. I always recommend adding it directly to your filter.
If kept properly refrigerated, B-S should instantly cycle a tank, as long as you add the fish immediately. No ammonia/nitrite/nitrate spike or anything. If added into an uncycled/crashed tank after fish are in there though, it may take up to 48 hours to eat up the ammonia/nitrites that were already present. And never use in this case, without a large WC beforehand. Especially if you used any kind of ammonia-removing product. That will definately cause the new bacteria to starve & die. I always recommend adding it directly to your filter.
