Okay, What's going on?

I'm not a complete amateur with hydroponics, aero dwc etc or any of that, I've done it for years. I work with restaurants so I'm turning a passion into a potential profitable experience. BUT....BUT I am not familiar with lettuce. so it leaves me with some questions that I've searched forever to find the answer to but can't. So, to start. this time around I will be building an NFT line with 9 or 10 gutters. I already have a bunch of supplies from past projects so I won't name everything. Well, each gutter will have 15 sites spaced according to the last stages of lettuce. I would like to harvest 150 heads a week. so above that station I will have another rack of gutters with the holes closer together for the earlier life of the lettuce, running from a different reservoir with less nutrient to avoid burn. at another station I will have the germination and seedlings grow. I understand that lettuce from seed to end usually takes around 30 days if it runs good. I may add another even smaller nft gutter. Since I'm trying to keep this a perpetual garden I would like to harvest the the adult heads, swap the lettuce from the smaller nft station down to the full nutrient station and the seedlings into the smaller nft station. It's hard for me to be clear so I apologize I'm in a hurry I need to leave. I was wondering if any of you could verify the timeline of lettuce for nft.

..for example..

seedlings will be in their trays for around 10 days, then bump them to the small nft for 10 days, then bottom nft for the final 10 days. Does that sound feasible?

If anyone has any cheap recomendations PPM and PH for simple nutrients for nft lettuce too for full strength and half strength I would love to hear, I'm hoping I can still use my existing nutrients lol.

okay it's getting dark. I know i had other questions but I can't think ofthem right now, Again I apologize for how unclear this message is, if you've got the time I'd love to hear from you other diy enthusiast

seeeeeee ya.