2x2 Tent Problem - Leaves Cupping/Brown Spots

[Sm0k3yMcB1uNt]

Hey all, I'm new to this forum as we just started growing and popped some seeds in January. We're growing Grapefruit Diesel from Next Generation. I wanted to know what you think might be my current problem? I was thinking it is heat stress, so today we raised the light to 30" (2½ft) and changed the temperature controller to 20-21.5°C (It was set at 21-25°C two days ago). Also, we noticed humidity was a little low this AM so we turned the mist setting up a tad to achieve 50-52%. I should mention that I topped the plants to the 3rd node yesterday, they were into their 6-7th node when we topped them.
To fill you in on our setup. Currently we are running two LED's (ONEO LED Grow Light 1000W), using Fox Farm Ocean Forest Soil and Remo Nutrients (got the supercharged kit) in 3gallon Smart Pots. We have been feeding every 7 days roughly depending on the weight of the pot, water PHd at 6.4-6.5. In the beginning we were battling humidity problems so we added a humidifier that can read and keep the tent humidity at 45-55% (TaoTronics Cool Mist Humidifier). Then we started having problems with low temperature, so we made the addition of a small heater (AmazonBasics 500-Watt Ceramic Small Space Personal Mini Heater - Pink) the heater is hooked up to a temperature controller (Inkbird ITC-308 Temperature Controller) to keep room temperature between 20-21.5°C. The heater is pointed toward the wall of the tent to avoid hot spots on the plants. We have a carbon filter running and it's outside the tent, it's pulling air out of the tent and into the carbon filter (iPower 4 Inch 190 CFM Inline Fan), this is accompanied by a smaller fan for air circulation that pointed above the plants (not at them) to help with circulation and hot spots.
Any help would or advice would be much appreciated, I was thinking maybe we could remove the heater if the problem persists and place it near to the outside of the tent instead.

 

[startergrow]

Many people here who know alot more than I do, especially with a soil grow but that seems like a lot of light while still realtively small. I thought you couldn't have too much light but had an issue in my small tent also. Not so much the light but the direct heat from them.

Hopefully backing off the lights will do it. Also it seems the most common answer to soil grow problems is with watering but you seem to know what you're doing.

You seem to have everything under control or at least controllable and to me it actually all looks great.

Some strains and grows go through issues. Often if you do what you can and keep the good care going, you are already doing, it all works out.

 

[Enr0n]

Plant #3 has what looks like a N deficiency due to the yellowing leaves. I am unfamiliar with the nutes you are using.

Raising the lights and monitoring the canopy temp might help. Are you feeding and watering the well?

 

[Sm0k3yMcB1uNt]

Thanks for the info!! Hopefully, by raising the light to 30" from soil today level it will help. We just added the second light into the tent the other day, but I will turn it off as many people have recommend it. Another person said they use the same light in their 2x2 and one will do fine for now. According the company, it's recommended that I use two lights for flowering which is why I bought a second light the other day. However, the problem began before I introduced the second light to the tent yesterday.

I just started giving them nutrients on Feb 3rd (Wednesday), and I water the full pot until there is around 10-20% runoff. There has been growth, but it's slow. It has been since January 8th that the seeds germinated and were put into jiffy pucks. The problem seems to have started around when I transplanted the plants from red solo cups to their final 3 gallon smart pots. They were doing fine up until that point.

Someone had mentioned that it could possibly be root problems from fully watering the 3 gallon pot with such small plants. I stared fully watering the pot after they got transplanted into 3gallon pots from red solo cups. They think that I'm overwatering the plants by fully watering the 3 gallon pots until there is runoff. They said in the first few weeks over watering can occur when too much water is added to a pot too big for the plant in it. They suggested giving it only 1 red solo cup of water every few days as needed based on soil moisture levels.

Thanks for all the help!

 

[Enr0n]

Here is my watering guide written by another member.
How to water your plant