Hey Bruce, as well as some drainage holes, I would add mulch to keep the soil evenly moist and also help keep it cooler now that it’s getting hot outside. The soil you have should be fine for tomatoes but you could also add something like Espoma’s Organic tomatotone. I’ve had good results with that in the past. When you have a lot of suckers, you get a lot of energy going into growing them rather than flowers so pulling the suckers off will help get more flowers. Tomatoes are self pollinating but, In the pool enclosure, you can always try and stimulate that process with a slight shake of the plant, to simulate wind (if there isn’t much air flow in your enclosure area) There are lots of pests ready to pounce at this time of year outside of your enclosure.. hornworms, stink bugs, aphids, shield bugs. Good luck!