Heating tank with tubing from central heating???

[maroun.c]

Hi,
considering linking my 400G tank to my basement setup of frag tanks and a big sump (total volume would be around 1000G + with room to grow)
To keep the setup temp stable I'm haiving to run 1750W of heaters constantly.
As I will be doing central heating pipe extension to the basement I am considering one of 2 options:
-Running part of the tubing in a loop shape in the sump and having it controled by a solenoid based on tanks temperature.
-or maybe having a separate tank next tot he sump with a loop of heating pipes in it. when the temp drops this would start a pump that will send water from teh sump to get heated and deain back to the sump.
Anyone tried such thing and does it have any risks/consequences???
Tubing used is plastic made (API) here so no risk of copper.
Any suggestions?

[worm5406]

PEX tubing would be best...

That would work perfectly.. I have hotwater baseboard pipes through-out my house.

Again.. make it like a double raditor.. they never touch each other and warm up as needed. The water temp in those pipes get hotter than a tank can handle though.. so I would be worried about a 'boiling' situation... Not bubbling... but cooked fish if something was in a failsafe of OPEN.... it is easier to warm the fish up than a cooked one.