leaf tips

I'll go with both Hashy and HerbalEdu on this one - a magnesium deficiency - but the question is, more accurately, WHY... Magnesium is a micronutrient that is only available to plants if the PH is in a good range... if the PH is out of whack, you can force feed pure magnesium and it won't do any good... So check the PH and get it in balance (runoff should be between 6.0 and 6.5)... If it's not in balance, do a good flush because you're most likely in a lock-out situation... run 3 gallons of PH'd water for each 1 gallon of pot size through your plant and then run a feed to them. Going forward, make sure you're giving them water/feed that's been PH'd and you should be good to go. If you don't have one, do think about investing in a good PH pen... Apera or Blue Lab are two excellent choices... Good luck!