I will tell right off the bat that cucumbers are very easy to grow with hydroponics. That is the vines or bush grow fast and well, pollinating on the other hand is not the easiest. Cucumbers are like the squash I posted about earlier, you need to take pollen from the male flowers and put on the female flowers and if you are indoors that falls upon you to do. There are apparently some varieties that you do not need to do this, they are self pollinating like the tomatoes.
If you do not have one of these varieties then prepare for some work. Unlike the squash flowers that have very large “parts” and flowers that make it very easy to pollinate on your own, cucumbers are very small in both aspects. On squash I would pull off a male flower and paint the female flower but you are probably better off using a paint brush on the cucumbers (or both just to be sure). Just take a small paint brush and twirl it inside the male flower (you may not see any pollen on the brush but its there) then paint the center of the female flower.
When I first started I bought some “bush” pickling cucumbers (totally by mistake). The plants and leaves ended up growing so tightly I couldn’t get to the flowers easily and their were tons. I ended up pulling them out and planting one in a DWC bucket outside the green house to let nature pollinate. After pruning it a bit and removing a bit of leaves nature did its thing and I harvested the first of the pickling cucumbers this week. Now I never had this kind before and I thought it would taste weird, thought it was called pickling cause it had a taste made for pickles. Go figure they are just like other cucumbers just shorter and taste great!
I now have three vining “slicing” cucumbers in the back of the greenhouse and the plants have already reached the ceiling! So remember if you are doing these indoors or in a greenhouse have plenty of room. They have been producing lots of flowers as well but mostly male. It appears Im getting the knack for pollinating these guys to as I have 3-4 maturing nicely.