first, the HPS is warmer than the t5 a small fan should do the trick if the ambient temp isn't over 72ΒΊ or so.

Second, a suggestion with the little microscopes. You can buy lithium batteries in AAA, which will give the best service. Otherwise the light gets dim very quickly and then the scope doesn't work for shtt. I discovered that using a mini flashlight with AA batteries (which I have plenty including rechargables) works great, even better than fresh batteries in the microscope. Lay the flashlight on a folded handkerchief or cloth on the table so it points right on the leaf you want to look at. Just use the scope with the flashlight. ramble ramble....