Sump build - skimmer question

[kniquy]

I am building my sump for my 75g- it is a 20 long. Anyways my question is what is the typical height for water level. My current skimmer is 7" but one that i am considering buying down the road is 9". I'm not sure what I should do for my skimmer compartment. I want to do it once and be able to change out the equipment if or when I buy a new skimmer. Look at those new cone skimmers.

 

[Sn8kbyt]

I would design it for the largest skimmer you plan on putting in there at some point. In the mean time using a smaller skimmer you can make a stand to raise it up in the water.