Kaya's Coffee

Last week I fought some yellowing of the leaves. Did some small adjustments on PH to keep it in the 5.6 range. Seemed to stop it from progressing. For Week 3 Veg I topped the plants. I plan to flip the lights at the end of week 3 and move into flower. Day 15 I continued to have yellowing leaves even though I had everything looking right. (Added Pic). I decided to look into the PH to see if I was having issues with it. I have a meter in the water 100% of the time taking a reading every 1 sec. It all looked right. But I decided to Calibrate it in 4,7,10 solutions. Found out that my meter was off. So new to the check list is to calibrate the meter before each grow. I was thinking my PH was High, when in reality it was low. put in some PH up to get it back to 5.5 and over the last 16 hours things look pretty good. Leaves look darker. Day 17 Things are looking good. Leaves are getting darker and new growth coming in. Day 18 Turned room temp down to 73F from 76F. Fearing it is warming up my res tank too much. Day 19 Starting to get yellowing again. checked everything and can't find a good reason for it. Did notice some cloudiness in my res tank. Added 2 ML/Gal of peroxide. have Hydroguard on the way to help. I'll be adding more fans this weekend. I have light air movement currently. Also found a few spider mites and sprayed Greencleaner to all plants. Current environment settings: Room Temp 72.74 F Room Humidity 63.63% (After spraying, Trending down). Room CO2 589PPM Tank PH 5.70 Tank PPM (500 Scale) 953 Tank Temp 74.05 F Day 20 Recalibrated my EC probe just to be sure it was also accurate. wasn't off by much. Dialed back my flooding to every 5 hours to encourage Rooting. <-- Strong roots = strong Plants Sprayed for mites