HydroHermit

Hey SAC87, I have been reviewing your journal through the flowering weeks. Your problem that led to the "Buds not Fattening" began between weeks 10 and 11 when your PPMs jumped to 1040 - It was too much, You unknowingly created an imbalance in your root zone that led to a partial nutrient lockout. Then you compounded the Issue with High daytime temperatures and Increasing the Wattage without much change in the Distance between Lamp and Plant. Looking at the Photos, your plants began showing intervienal chlorosis and up curling of the serrated edge shortly after you made the changes to your Grow environment (Bulbs, pH pen). As the weeks progress after the initial insult to the plant, the Increased wattage and temperature began burning your leaves as demonstrated with the darkening color and crispy textures that soon became Yellow/Light brown. The damage to the leaves significantly impaired your plants energy production causing the flowers to stall out compared to previous gains. The appearance of Banana's as you have described further indicates excessive plant stress that is causing hermaphrodite'ing - At this point, I am sorry to say but You might have already lost the Battle.

I agree with the OP - you need a way to manage your nutrient solution temperatures. I would recommend 66 to 69 degrees F (18.9 to 20.5 degrees Celsius) And yes 5.7 to 5.9 pH is ideal for Hydroponics but you do have some wiggle room. Chillers can be expensive, until you are able to acquire one, You can utilize products like "UC ROOTS" or "Watermax" or other products that contain Hypochlorous Acid which increases the ORP value of your Nutrient solution and makes it more Bacterial Static. Your air pump is a good size at 16 liters per minute for your approximate recirculating volume of about 20 gallons. You may need to consider adding more Opacity to your grow modules to seal out light infiltration within your root zone, otherwise it looks like you are ahead of the game for a first time Hydroponic grow.

I'm confused as to why you have documented a pH of 5.5 in veg and a pH of 6.1 in flower.