125 gal sump

[LS90gal]

Hi All
Today my buddy reached out to me to help him make a filter system out of a 125 gal tank which he will be using for a sump. He has a 300 gal tank.
I have a 90 Reef tank that has a 30 gal sump with sock filters, phosphate reactor, macroalgae section, protein skimmer. I also have a decent amount of base rock in the sump.
My questions to you guys is since he will be need a good amount of rock in the sump is there it ok to use lava rock or florida reef rock to get the same results for a biological filtration.
How much of the rock would we need in the sump ?
I am looking to run 1 return pump that is quite and doesn't suck up watts any recommendations?
Open to any suggestions

[dave.m]

You don't "need" any rock in the sump. It is a nice-to-have addition if you have room in the sump and think you won't have sufficient rock and substrate in the display tank to meet your inhabitants' needs.

I like to use filter socks in the sump. Some don't.

You might choose to have a section for filter socks, and then follow it with a section for an internal skimmer, then a section for internal media reactors, then a section for dosing, and finally a return section.

If you opt for an external skimmer running out of the internal media section of your sump you could free up some space. If you opt for external skimmer and external media reactors you could free up some more sump space.

You could have a high-flowthrough section in the sump for algae filtration or some live rock. I would never use lava rock on a reef tank - too many unknown minerals of dubious origin.

Another option would be to set up a separate tank off the sump for live rock. You could light this to encourage algae for additional filtration and to act as a refugium, or you could darken it and use it as a cryptic filter. Lots of possibilities for you to consider.

Just some ideas for you to mess about with.

Dave.M

[LS90gal]

Tanks for the reply,

[LS90gal]

Tanks for the reply,