I just got a 18 inches ponytail palm (the trunk only) , and 9 pieces x 1 inches baby ponytail palm (also trunk one) frm nursury. When i first got it, it was in very wet soggy soil. I repotted it in perlite, aquarium coarse sand and quality pine bark chips. No peat, no soil. I also mixed in about 1 table spoon of osmocote 15-9-12 in a pot of 17 x 8 inches round tetracotta pot with 9 others baby ponytail palms.I use 1000 watts grow lights, 16 hours a day. It is now with fan blowing on them after i noticed yellow new growth.The first 4 days i water it once a day. Because it is in gritty mix. Then i stopped for 3 days until the perlite feels dry. But on the 4th day, the baby ponytail shrink. The big one didnt.Now, the big one, the yellow leaves turned reddish or brown.Is my plant problem due to overwater, or sunburnt? Or it is from osmocote? Or maybe soil mix? Thanks in advance