Waterbox Cube 20 Chamber Allocation

[OceanBB]

 

Hi everyone, new to this hobby. Got myself a waterbox cube 20, just started cycling my tank yesterday.
Need some advice regarding the chambers. Currently : 
Chamber 1 : inTank media basket with filter floss. Will add chemipure once cycled.

Chamber 2 (middle) : Syncra silent 0.5 feeding Aqua UV Advantage 2000 hanger steriliser.

Chamber 3 : Aqua UV hanger return (from chamber 2), Eheim 100w Heater, Eheim compactOn 1000 return pump.

Few people pointed out that heater probably safer to be in middle chamber (Chamber 2) due to risk of running dry in chamber 3. But since their is also a pump in middle chamber pumping into chamber 3 (via steriliser), the risk of running dry will be the same for both chamber ? Should I move heater to middle chamber ?

Last equation, where should I put the Tunze ATO sensor ? Chamber 2 or 3 ?

Thank you so much for your time and input.

[Clown79]

Not really sure to be honest. 

I don't see many running a steriliser in their tanks. Otherwise, yes, the heater shouldn't be in the return chamber

[PeterU]

8 hours ago, OceanBB said:

Last equation, where should I put the Tunze ATO sensor ? Chamber 2 or 3 ?

Your ATO sensor needs to be in the section that is seeing the water level change. This is normally the return section.