Unreal just makes me want to start DWC right now are you doing a water change or are you just topping up... ? please make sure you keep us posted i want to see this girl finish
It may seem redneck, however if you're running RDWC like I am, you can put a frozen 2 liter in the heart/res with another one always ready to swap places. It seems like a cheap, stupid method, but it worked when I had to make it through hell of a rough summer and didn't have 300$ to throw down for a chiller...also, cool air blowing directly on your buckets and allowing your air pump to suck in cold air from outside/an ac unit in summer can really help as well...more than you'd think.
P.S. If you have pythium problems, sterilization IMO was never very effective...I caught pythium 2 weeks even using H202. However, I bought hydroguard and didn't only see an explosion in root growth, but a total stop in any form of pythium...I think anyone using DWC should investigate using bennies...although Hydroguard is all I've used, I think it may be one of the best products with bennies you can buy...you could always make compost tea...
*EDIT* I meant to quote the person asking about maintaining water temps, sorry DirtyNerd!