Pulled the trigger on an XP4

[chiphead]

Thanks to the help of the folks here I purchased last night a Rena XP4 and two Hydor 300W inline heaters for my 125 tank. Tank holds two 10" Oscars, a 12" bullhead cat and 4 other 4-6" cichlids. I'll keep my Cascade 1200 and use that in conjunction with the Rena. I ordered everything from Kens Fish. Even after applying a $35 dollar gift certificate to Amazon, it was still about $9 cheaper to go with Kens.
Now the big question is I have a HOT Magnum HOB. Can I leave that and put the polishing filter in it and just run it once a week for a few hours? Would the water that sits in the filter for a week while it's not running have an adverse impact on the tank when I start it up?
Thanks.

[Weezer]

I would continue to use the H.O.T .......:)

[ChrisK]

Just keep using the hot, extra filtration will not hurt.

[Cory Keeper]

I'd continue to run it, more filtration the better.

[RodInCALIFORNIA]

i run my HOT magnum just to polish the water along with the regular filters I would run it full time.

[chiphead]

i run my HOT magnum just to polish the water along with the regular filters I would run it full time.
Rod, you use the polishing filter full time? How often do you clean it?