If you were worried about stump remover you can buy bulk potassium nitrate powder for dirt cheap at green leaf aquatics. I think I got 2lbs for $6. Id be more than happy to share some with you. I haven't used it yet as I got my sps to color up by overfeeding, adding fish, and feeding reef chili/roids everyday. And I still have zero nitrates! You'd have to play around with the dose but Rudy mentioned a rough ratio to me that I've forgotten but there are loads of scenarios online. I'll probably try it at some point but didn't want to move too many levers at one time! Let me know if you want some, I'll be at the meeting. Sent from my iPhone using Tapatalk