There are a few options for keeping water temps lower.
- Remove the back lower right door and allow a fan to blow directly at the opening. This is in the hope that your ambient temp sits around 70F. If you live somewhere like me (AZ) this isn’t affordable during the summers, or any time other than winter for that matter .
- Frozen water bottles. This is a ginormous PITA since they have to constantly be rotated, however it’s cheap and easy.
- Install a chiller. This is probably the most expensive option though it also seems to be the most reliable. I run a chiller for my two buckets in my tent and never have to worry about root rot.
If your current water temp is 74F, hydroguard should work just fine. When I hit summers here, I do 10ml every water change and keep an eye on my roots, check once a week during water changes to make sure they aren’t getting dark and slimy. If a chiller is a route you’re willing to explore, there are a couple write-ups on installs here.
As for internal temp…this should come down after day 11 when your intake fans start to run. I think the lower is on day 11, don’t remember when the upper comes on.