External skimmer positioning

[Joe Batt]

I have only ever had internal in sump skimmers before. There was an optimum height for placement in the sump.

I have started a new tank with an external skimmer. How do I control the lowest level of the water in it? Do I control it with reference to the level of the water in the sump? For example if I need the water level lower I need to raise the skimmer with reference the sump waterline

At the moment (as per the diagram) the return flow goes back to the sump via a diagonal pipe and with the skimmer feed pump off the water level sits at the level of the highest point of the return line. It is mid point in the neck of the skimmer. The problem is if I need to raise the skimmer in will need to come out of the cabinet it is in since there is no head room

 

[77.christy]

Not sure I understood the question correctly, but I have an external deltec on my 140. I have it on 6” feet only bc of my drain. I needed to raise it for the drain to be higher than my sump and have fall. Otherwise, it couldn’t set directly on the bottom of the stand. Is your drain pumped? If not, im not sure how well it will drain per your diagram. And if like mine, the drain is on a bulk head and you could swivel it to lower it from the top of the cabinet... I control the flow/water level in the skimmer with a valve off my return manifold.