Thanks DW. I split it yesterday and now have a 40 gal for the NFT and a 55 gal for the dutch buckets.

This great. My challenge remains on how best to manage the nutes in the reservoir over time. Farmtek tells me to completely change out the reservoir every 2 weeks. But then I read where others adjust the ppm to certain levels based on the plant and growth stage. I was mixing my nutes 5 gallon at a time but I'm going to change that to 40 gallons at a time to make it easier.

I have 4 12-slot nft trays with 1 tray in bok choi and the rest in butterhead lettuce. It almost seems like too many plants for a 40 gallon reservoir.

For NFT i try to keep it around .75 gal per plant. I am sure you could get by with less but I had a spare 40 gal laying around. On the dutch buckets I have 18 plants on 50 gal.

The NFT system that I have from cropking has a 40 gallon reservoir with 4 12-slot trays. So, that matches up pretty well with your numbers Mark. I was wondering if perhaps my tank was undersized.

.5-1 gallon per on lettuce is great, choy I would use a minimum of 1 gal each as they get big and feed pretty heavy. 40 gal is perfectly fine on either system you are running. Once the BATO buckets fill up and get big you will be wanting to change out around 2 Weeks but to start them the first month as long as you get no mold/algae/seddiment you will not need a res change as they plants won't be feeding in large quantitys. Same goes for the nft in the first 3 weeks, you might be able to get a full cycle of lettuce (30 days) out of it. Just keep an eye on lvls and PH