Hello PaulF,
You did a great job on a budget. As for the temp that might be a bit cold. 52 with the
lights off (night time) shouldn't be much of a problem, although 65 when the lights are on (daytime) will probably be a bit cold for everything other than the lettuce. Especially the peppers that I believe are a warm weather plant, and prefer temps 80 degrees (F) or above. You might experience slow growth, and/or a lack of flowers/fruit on them.
Also I would wonder about the water temp, temps below about 65 degrees (F) will also add to slow growth. You can use a fish tank heater to help keep the water temp's in check. Just get one that has a adjustable thermostat and try not to set it above 72 degrees. Also make sure it stays submerged in the water, but not in contact with the plastic tubs. Water temps above 75-78 can add heat stress to the plant, above 80 can cause the plant to stop or abort fruiting.
Personally I think you will find that cucumber and tomato plants will be to big for that space. What is that black tube looking thing the bubbles are coming out of? Does it stay down at the bottom of the tub without weights?