Leaf tip curling

One of my babys is about 2 months old now, but it looks like its growth has slowed down a bit.
The ends of the leaves are curling down and new small leaves are really bright green at the centre.

I figured it was a magnesium deficiency, so ive watered it twice with epsom salts, but there has been no change.
I'm worried that if i continue to try, that i will lock up its roots (if i have not done so already) so my other alternative is to flush it for a while.

Does anyone have any advise?

I will also post some pictures when i get the chance.

Peace

i would flush for a while leaf tips curling down means over fertilized

need pics, could be overwatering or slight nuteburn or ph issues causing nute lockout like you suspect or too much heat or not enough of one specific nutrient(does your feed have micronutrients in it?) or.....i could go on but you get the idea. give us detailed info related to the things i mentioned and the pics asap.