Hi all I want to update heaters before any issues occur. I am replacing neo therm. Heaters work great but want to also clean up my sump. you will see in the pic they are in the skimmer chamber. I want to make room there for my mini brs reactor and in the front chamber start a refugium. So that leaves a fairly good spot in the overflow section of the reefer 250 sump, but its only 11" tall. I am running an Apex but do not want to use it to control the heaters just as a failsafe backup. So here is what I am thinking 3 - 75w eheim old school glass or a couple titaniums controlled off a inkbird. I am open to other options as well. Thanks for your help. Again it a red sea 250 ... so 65 ish gallons and temp in the house never really drops below 65.