^^ I think Rusty has it right as usual :greenthumb:

But for next time - Have you thought about 5 gals instead of just the 3gals? You can get away with the 3 gals with clones, but the root systems of plants from seed are much larger and also like to have more room to stretch out.

I've also noticed that transplanting a week or two into flowering to a new pot helps with the problem of ph drop/buffer depletion.