Hempy Possible Overwatering?

[hempygolucky]

Hello! First time grower here.
Basic Starter Info:
Running two 3 gallon hempy buckets in a 100% perlite mix except for the rapid rooters (germinated seeds in them straight in the perlite.) Using the GH Flora Trio (No bloom at the moment) and Hydroguard. 600W LED Grow light 18/6. Humidty has been 60-65% and temps average 82F with the light on and 76 with light off. One small fan blowing against the wall in the top corner for circulation. PH stays around 6 but don't know exactly because I'm using the color chart method.
Strain is Phoenix Seeds Northern Lights Auto.

I water once/day to 30-40% runoff and have fed with every watering from seed. Currently a little over 2 weeks out from seed.

Questions:
Plants seem pretty droopy. The one with more green algae has been somewhat droopy but still growing consistently the entire grow. Any ideas on what's causing this? I was told with hempys its almost impossible to overwater, so is it underwatering? The one that's been consistently droopy has also had a slightly red stem the entire grow- is that anything to worry about? (Was thinking magnesium deficiency but have no idea.) The consistently droopy one also seems to drain slower and I always come back to find runoff in the tray a full hour later.
Should I add cal-mag? Water less? (not even sure when I can tell if the roots have hit the res and the res is definitely full)
Also I've heard that green algae is normal on the top of perlite in hempys. That hold true?

Thanks in advance for all your help! Long-time lurker, first time grower, and somewhat anxious.

 

[Gone Camping]

I ran hempy for a bit as a newer grower. In 3 gallon buckets and at two weeks I would think the roots havent settled in to the reservoir yet. But you should be there very soon, and you'll notice them taking off.

Typically I'd feed with little runoff in the first few weeks.. it's just waste. Even feed lighter twice a day just to keep medium nice and moist.

 

[hempygolucky]

Ahh okay thank you for the flag on the buckets and roots settling into the resevoir- I wasn't sure how to tell/how long that takes. It seems likely that I can't be overwatering because the stem is straight and there's a hole to drain- so is it possible that I'm actually underwatering and just need to do smaller amounts more than once per day?

What do you think might be the cause of one plants droopiness if the other is being treated exactly the same and they're the same strain?

Thanks again for your advice! I really appreciate it!