HDD Cooling in cosmos?

Hi!

I've a Cosmos 1000, but this should apply to all Cosmos I think.

I got many HDD's, 10, at first I had to place them wherever I could inside the case, once I screwed two of them to the ceiling of the cosmos and had two fans blow air directly to them.

But then I watercooled the system so I had less space... I moved 4 of them to a separate dedicated case. So 6 remain, 2 of them are 2.5" SSDs so I put them in an enclosure in a 5.25 bay. 4 remaining!

There's not space for them in the 5.25" bays so I have to put them in their intended place... those 6 bays in the bottom... Right now I can't use one of those disks since I need an adapter (I broke the plastic L on the sata connector, I still got it but I wanna put it in an 90° sata adapter so I could change cables in the future) so I put the 3 disks one after the other. They get HOT! One of them it's at 56° right now

Is this ok? I guess the cooler the better of course but maybe they're designed to work in this temperature range... anyway I'd like to cool them. Watercooling is out of the question since the blocks are too expensive IMO. So I'd have to resort to fans but I'd like to know the creative ideas some of you have done. Maybe I could just glue/screw/velcro some 9cm fans to the caddies but probably there are more aesthetic ideas out there

Thanks!