Lemon Diesel, Sugarplum, and White widow (first grow)... How am I doing?

This is my first grow and I feel like everything has gone fairly smoothly so far besides some ph issues I have been having, which I need help with! They are on day 37 of flowering I have them under 1 1000w Metal Halide and 1 600w HPS, I am working on getting another HPS to replace the Halide, but it has been working fine so far. I use "Bloom Terra" for the nutrients. Other pictures of people plants in 5 weeks seem like they have bigger buds, so it worries me that mine aren't growing to their maximum potential. Any pointers on things I can be doing to maximize growth? I try to keep the temperature around 75 during the day an 70 at night, is that about right? Any other things I might be missing? Hmmm, heres some pictures.

Bumpity bumpity bump

Looking good.

Can you describe what you think are pH problems?

One thing I always do (growing in pots with soilless mix) about 4 weeks into flower is to really flush my plants assuming there will be some salts built up. To flush, I use pH'd water (around 6.0) and make sure I get at least a 1/2 gallon run through on each plant (#5/#7 containers), which I discard. You should take your time in the process too. Give the water time to really saturate the medium. After flushing, I let them dry out for a couple of days.. next feeding is about 2/3 of normal (I stay on the weak side) and only basic flowing nutrients. If I've been having problems, I may flush them one more time the next week, but usually resume any flowering additives.

This method is also my first go to if I'm having any sort of nutrient based plant issues.

Hope this helps.

Peace,

Farmer Rich