What should I do with my NFT System and greenhouse space?

Hi everyone,

It’s the end of my growing season and I’ve harvested all my potatoes, cucumbers and other crops. Now I have a lot of free space in my greenhouse and I’d love to turn it into a year-round project that could also bring in some profit.

My current ideas:

I want to create an aquatic plant nursery using the floating plants (Salvinia, Red root floaters, frog bit and water lettuce) I have already have in my collection (see pic 5) and plan to propagate them for resale on eBay and Etsy. I’m thinking of building a large raised-bed style tank (1.2m x 60cm, 5–10cm deep), waterproofed with varnish and pond liner on the right hand side next to the hydro system.

For winter, I’m not sure how to keep the water warm. I don’t have electricity in the greenhouse, so I’d either need a long outdoor extension cable or try something like a compost heating bed or even a thermosiphon (though UK winters might limit the solar option).

On the back stand, I plan to build small A4-sized shallow containers for sorting plants before shipping but these will still act as a final stage for it will still grow more as it is separated into its varieties.

My NFT hydroponic system:

I built one but haven’t grown anything in it yet. The issue is I don’t have caps for the ends, so it’s hard to get water trickling properly between pipes. My solar pump works but I’m not sure if it’s strong enough for the flow rate.
I have a small reservoir with net cups at the end for the whole system.

– what would be a good herb/plant to grow here that could actually turn a profit? Any tips for making it more self-sufficient?

Other ideas:
Would it be worth trying to grow moss on a small-to-medium scale? I could grow it under the hydro system, but I don’t know if it would be profitable compared to just sticking with aquatic plants. I have a small collection of different types and I’m about to go on and sell a workshop that involves moss and I wanted to be able to produce it from my greenhouse rather than sourcing it.

I’m really passionate about making this space both productive and profitable, so I’d love to hear your advice:
• How should I heat/manage the aquatic plant nursery for winter?
• Any ideas for crops I can grow in the NFT system that sell well?
• Is moss worth trying or should I focus fully on aquatic plants?

Thanks