[Delphinus]

If you're handy (REALLY handy), Home Depot sells HRV's and you can install one yourself for considerably less.

I ran a dehumidifier for years (boy you get strange looks when you buy a dehumidifier in Calgary), but, they are noisy and the effect is localized at best and as soon as you unplug it the humidity jumps right back up.

80% humidity is going to be a HUGE problem down the road. Weeping windows when it's cold outside, damp walls leading to mildew on and in the drywall. I had the same problem, 6 months after moving into my current house I had all of the above, and the dehumidifier was running 24/7. This was with a 2 reefs - a 90g, 75g; and a 30g FW in the house. Really not that much volume of water and the damage was astounding. The problem is as stated that houses are more and more airtight these days so the humidity has nowhere to go. I was faced with a critical choice: scale back or quit, or install the HRV.

It hurt to pay that much but it was worth every penny. In fact, the more I learned about HRV's, the more I realized what a great idea they are. I will never not have a HRV in my house again - even if I don't have fish tanks. They're that good of an idea. As stated they ventilate air but unlike an exhaust system, it replaces the air pulled out and uses the exhaust air to preheat the incoming air at something like 80% efficiency (ie., 80% of the heat of the outgoing air is recovered - very important when it's -20 outside!)

AirPro Heating did mine. I got 3 quotes - Fagnan's, Sears and AirPro. AirPro was not the cheapest but they impressed me enough that it was worth the price - sold me a better high end unit, a better understanding of the problem at hand (they were very interested to learn about the fish tanks too!) and just did a better job of explaining how the HRV was going to solve the problem and what sort of sized unit for the required air turnover and so on. I'd recommend AirPro in an instant to anyone. Hopefully they're still as good these days.