You can add methal hydrate to the tank, but I dont beleive thats going to solve your problem. As suggested before, Increase your line size to 1/2 inch. Also while your doing this, move the filter inside. The inside of these filters gel up to the point that it looks like somebody sneezed into it. Not only does it make sense to move the filter inside, its code compliant. I like the cartridge style filters better than the canister style. You get better flow thru them and are cheap to replace. Good luck, I hate working on these things when its this cold out. John B.