Blue Dream - amateur learning as we go

She seems to be growing every day slowly and has been stable! We haven't been getting much sun so I've been using the grow light (in conjunction w/ natural light) starting about sunrise to midday, and then again from around 6pm to about 1AM. I added MycoBloom (Mycorrizhae) on 05/15 but not sure if that has done anything since roots already established. I try to only water every 2-2.5 days but it's not enough on sunny days. the tomatoes seem to have the same water needs and soil moisture. I've been filling up a 2 cup mason jar and splitting that between the 3 plants so maybe 0.67 cups of water each. I'm not really sure how I'm doing but she seems to be growing and progressing each day so I'm hopeful. To do: Buy something to monitor soil pH? Buy something to monitor water pH? Probably will have to buy a stronger LED if she keeps going well. Thinking the Roleadro off Amazon that is 1500w and goes for about $110.00