The tent is in the garage which is attached to the house. Temps have been pretty consistent apart from a spike early last week at around 29⁰C if that's where you're aiming?
first off all I’m a garage grower aswell, and I can understand the constant temperature swings.
regardless of you air temperature, it doesn’t mean nothing.
your ground temperature will always be letting cold in regardless. This obviously effects roots temperatures, which should always be hotter then air temperatur look it up. Organics rely only soil microbility too feed break down organic matter to feed the plants. This doesn’t happen, if they ain’t warm enough.And I bet the soil knever drys out regardless even if you pour small amounts of water it’s always wet.
you have a few choices. Get a radiator too heat the ground and roots, this should help you out Loads.
most likely your roots are already done with as the same with my plants, luckily I survived,
but I’m talking from experience:
next time either do a full grow in advanced. While your feed with chemicals. Your feeding your roots directly. Entire process of temperature! And you will more quicker growth. This will avoid Laos’s of problems !
If Make sure you did a good 10 days plus flush. Using flush for the first 5 days and then plain water.
good luck bro
try a more of a coco and soil mix with perlite!
I’d personally get a peat and coco mix.