Designing a new Sump.

So, i've got a spare four foot tank and i'm wanting to redesign it a little bit, changing some of the baffles so the water flows THROUGH it rather than just going over the top because all the baffles are flush on the bottom.

Heres the pic, i'd like any input as to how i could improve it. Keep in mind, i'd like to eventually add on a phosphate reactor and also calcium reactor, but i'll have two sumps running when i add my 6ft to the system (will have two displays, two sumps in the same system) but for now i want to swap over the sump on my four foot tank and if i can redesign my spare 4ft tank, i should be able to swap the two over in a couple of hours.

Heres the design.

I see what you are trying to do but I disagree with most of it.

This style of filter that can be done in many different ways, even vertically using storm piping, which mine will be next time, is what is pictured that I would always recommend in relation to longevity and practicality.

Gas exchange for PH balance, nitrite and nitrate oxidising to lesson the sickening affects upon fish and corals.
The filter pictured is designed as I always do to add to as a modular type of thing.

Take out the protein skimmer and add another section for fish refuge or what ever in line to over flow from one to the next and put back the protein skimmer at the beginning again.

I can't have my skimmer outside the tank, at least not the one i have at the moment. Will be able to have one outside when i build one to suit though.

I was thinking of where the water flows back up, putting in an area only slim, but the width of the tank and having coral rubble, and those ceramic rings. Also was thinking of having a wet dry section on the last bit where the water falls down into the return area.

What is the water flow direction on your design?

It goes into the 100 micron filter bag from the tank than the the arrow going towards the return pump is the water direction.

Its gravity fed,what the pump pumps in returns and gets pumped back up.

Ah okay. I gotcha now.

What goes in the drip tray and the two plenums? I was thinking of a DSB in my refugium area.

Just remember a refugium is a trendy thing in the ways they are used now,they were for use as a refuge not for anything to live in there,plant life or not.

An algae style scrubber will do far more than the trendy refugium will in reducing nitrate and phosphates.

To get a good result with a outer tank filter(sump),firstly a protein skimmer,very good prefilter bag,dry section,deep sand bed,carbon filter,scrubber and return to tank.

My refugium will most definitely house caulerpa, so it will be a fuge / algae scrubber one one section. My current one also has a light and a lot of caulerpa in there, except there isn't as much flow through it as i'd like.

I was planning basically..

Outlet -> Filter bag -> Skimmer -> Refugium / Scrubber -> Rock area / fish holding area -> flow over a big foam filter sheet (wet dry area?) -> return pump area.

All of that sounds great, but it is the long term I always look at with a marine set up and any and all filter styles work to some degree.

If you put a sand bed with algae you have to remember that the algae is based on some calcium to support it and than there is the cellulose structure and both of these contained and continually added as waste with in an area of any substrate that is not cleaned all the way to the bottom of that substrate will become blocked and begin to not oxidise waste gases and will produce subsequently commonly made unwanted gases like sulpha.

All but a few life forms are based on some kind of material to support its structure and as they shed or die this becomes not so much a polluting material but creates a blocking affect in the porus areas of your substrate.

If life is in these refugium, than a substrate should not be in there for the long term health, not 6 months or 1 year, but for the next 2 or 8 or 15 years.