Getting water back into the reservoir without gravity?

Hello everyone.

I've been rebuilding my tents and wanted to know if there was a method for getting the nutrient run off from say a dado bucket or ebb and flow flood tray back into a reservoir.

The reason I ask is I know I could elevate the trays off the tent floor with a stand but I would be losing significant room in the tent about 1-2" depending on table height and reservoir.

So ky idea was to maybe use a smaller tote about 17 gallon to catch the run off with a "seaflo" bilge pump that has a trigger mechanism inside that activates when it detects water (they use these in boats to pump out water) to pump what is in the "run off" tote back into the main reservoir.

Is this the best method to do this or is there a method im not aware of?

My reason for this is a reservoir outside the tent has always been my practice to try and keep reservoir tempertures lower than inside the tent.

Im growing tomatoes and peppers so this tent will be warmer than my other one housing leafy greens herbs and strawberries.

Thanks!