Leaves turning yellowish and brown color.

[crismobz]

This is my first grow. I'm using a 32' 32' 64' grow tent, with a 6 inch carbon filter and fan. I have the filter on the outside with the fan on the inside with ducting connecting them and running to cracked window. I have 4 plants, all autoflowers 2 Northern Delights,1 Afghan Kush, and 1 Green Crack dropped in 3 gallon smart pots. I'm using Coco Coir Perlite mix and Fox Farms Trio Nutrients ( 2 tsp of Grow Big, 3 tsp of Big Bloom, and 1 tsp of Cal Mag Plus per feeding). I tap water that has been sitting out for at least 24hrs and ph'd between 5.5 and 6.5 I'm using a 315 Cmh with 3100k light on a 20/4 schedule. Temperatures run between 68°(early morning with lights off) to 81° with tent closed. I normally keep it partially open with a fan blowing over my babies.They are about 4 weeks and have been doing great. Up until this morning. I was checking my babies and saw spots on the leaves and some holes. I researched and one looks like a calcium deficiency but I'm not certain and definitely need help. Please help, I've attached pictures

[Chefbjy]

Have you checked for pests. Looks like something has been chewing on em. Maybe gnats.

[crismobz]

I did have some gnats. I was able to kill them but I haven't seen any more. I checked for other pests and I didn't see any traces.

[Chefbjy]

Maybe left over damage showing itself...But I'd check again real good. Sticky traps could help spot them if you don't see them. I've been dealing with gnats in my shop. I go in and there's no gnats but I have found dead ones and that attracts the live ones

Also there could be another part of the area they are coming from aside from your medium. You can also try a trap using apple cider vinegar sugar water and a drop of dish soap see if you have any floating or sunk to the bottom of your trap. I've looked again at the pictures and that's my thought maybe someone else will chime in. ✌

[alltatup]

Post deleted: incorrect info. Thanks for correction Chefbjy

[Chefbjy]

Biting gnats or noseeums do and so do fruit flies which also look like gnats.

[alltatup]

Hi Crismobz, It looks like 2 issues to me. First pics, I agree with Chefbjy, and I think I see a different symptom on the second to last leaf, that looks like the beginning of some kind of nute problem. If you've overdone the nutes, give her a nice flush.

As for pests, there are lots of safe sprays: https://www.growweedeasy.com/safe-cannabis-pesticides

[Chefbjy]

Yeah I have seen that from pest damage as well, but could very well be. Was your coco buffered and what is your ec? I didn't recommend a spray since it looks to be flowering. Think there's some good stuff you can still use at this point though.

[crismobz]

Thank for the info! I used Cyco Coco Coir Perlite Platinum Mix,so I'm not quite sure what you mean. I think it was definitely pests and when I checked my journal I realized I added an extra tsp of Grow Big smh. I'm flushing now. Again I appreciate it y'all. What would you recommend for Pests since they are starting to flower?

[alltatup]

I sent you a link above; you can see what's best for flower.

[crismobz]

Ok thank you.