It would be best you mention what's the minimum dimension(such as to hold a certain skimmer) and the maximum dimension, such as limitations of your space. Or else you may be flooded with too many offers not suitable for your case.
Not really sure what the correct size you are supposed to use on a sump/refugium for a 75 gallon/
Ok I looked at it and maybe I am stupid so help me out That is a sump/fuge Correct.
I asked earlier and no one answerd
A basic sump the water goes down and UNDER a baffle and back up
with a combo ( as you have) the water goes down and OVER a baffle correct? There should be no difference in design between the two types
so each day I and everyone else who does nto have a auto top pff adds water to their sump Luckily the sump goes under so when it lowers it does not stop In general you should have enough margin for it to run for more than couple days without intervention.
So I think and maybe I am wrong with a combo when the evap happens the water drops in the sump so the water cannot go over the baffle so the pump side which returns the water will pump it all out and empty correct? One should not let this to happen because it will burn out the pump