- What is the best chemical composition for the mixture?
- Where can we get it?
- What feeders are good for it?
Animal salt-licks would be my 'best guess' too - but it's only a guess. I've also frequently thought about supplying a dose of those trace elements which are added by NFT (Nutrient Film Technique) growers to their solutions (seeing as I've already got a few packets of the stuff in stock). After all, such microscopic amounts of relatively rare minerals (cobalt etc) are essential requirements for many plants which produce pollen. Well - it's theory ...I used to put out a high mineral salt lick for the deer and the bees were all over the ground around it.