Pete ....
Sorry about the budget thing, I can relate !
You need an overflow man !
The fiasco will continue using 2 separate powerheads. The water levels will never balance out, and it will be unreliable.
Something is going to get wet - most likey the carpet around your tank, the wood floor under the stand, and your knees as you're sopping up the water on the floor with a towel.
Wives don't normally like that too much
Or you'll end up burning up powerheads from running them dry.
If you could raise the fuge up above the tank, like on a shelf or something, a bulkhead and a few bucks worth of pvc fittings/pipe would get you where you want to be.
I've even got a 1" plastic bulkhead I could mail to you or one of those mailing places if you want it - freebie !
Then you could have one pump pumping the water from the display tank up to the refugium, and this side bulkhead drain and piping/hose to gravity feed the water back down.
No pump in the refugium allows you to lay down a nice sandbed, add some live rock, and pack it full of caulerpa.
No brainer - very reliable - everyone's happy ( maybe )
Would this possible or not an option ?
It would not kill the budget, but would certainly attract attention from your better half
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)