[Phyxius]

I used a 1/10th PCI chiller on my 65 and it worked well. I upgraded to a 90 with 2x250MH and 2-VHO supplements and moved the chiller over to use it on it. It kicks on and off during the day and runs for not very long BUT I do have canopy fans and a 6" sump fan running to help cooling. It keeps temp at 78-79 all the time with the chiller with a house at 77-78
I`m planning on going with a 1/4 PCI chiller in the future to use on this one and then a 180. The 1/10th will go on a 29 with 1x250 and VHO supplements. It also runs fans but tips the 81 mark consistently.

You want a 5 degree drop in temp so I would go with a bigger unit like the 1/6 or 1/4 PCI. The 1/10th could work but it will be running much much more to do it