Will this custom designed Sump/Refugium Work?

[LarryS]

Hello again:

I am continuing to develop my 45gal reef setup. Due to space limitations under the cabinet, I had to design (with help from many others!) the sump/refugium in two separate sumps, connected together under the cabinet, so they could fit. Although the cabinet is 36" wide, there is a 5" vertical "style" separating the 2 doors to the cabinet, which I am not willing to cut, remove and replace.

I am going to have the sump/refugiam fabricated by a local plastics store, so before giving them the dimensions and diagram, I would sincerely appreciate input concerning whether my design is practical, workable and efficient. Here is a link (hopefully) to a diagram of the sump/refugium:

RefugiumDiagram

I have several questions about this setup which I would appreciate comments on:

1. Since the water must flow from the refugium to the return through a 1" diameter opening, I do not want sand to be sucked through, so I have a 6" retaining divider, which should keep the sand in place and allow water to flow over and then through the 1" opening, into the return. Will this effectively keep the sand in place?

2. Is there any reason I would want the retaining divider higher, and if so, any negative consequences to making it higher, say 9"?

3. Is a 1" internal diameter opening sufficient, or should I do 1 1/2 opening? (taking into account elbows and the return bulkead 4' up from the pump, there will be approx 8' or 9' of head reducing the 950 gph to approx 500-600gph. I will also add a "T" inline with the return on the outflow side of the waterpump, and add a ball valve so I can return some of the flow back into the return, if the flow rate is too high.

4. I have designed the opening only 2" up from the floor of the sump, to avoid the risk that evaporation will stop the flow to the return area and have the pump running dry. Any thoughts on whether there is an advantage or reason why the opening should be higher?

5. I am concerned that with the Protein Skimmer in the return area, there is a risk of excess microbubbles being pumped back into the display tank. My severe cabinet limitations compelled me to place the sump here. Any ideas on whether I should be concerned about excess air bubbles, and if so, any thoughts on how to minimize it?

Any other areas of concern or thoughts which I have not considered due to being a marine newbie, please share with me. I can't wait until the planning is done, and I can actually see a live inhabitant in the tank!!!

 

[OrionGirl]

I think the divider will work to keep most of the sand out--initially, you may have some swirling around, but it should be enough to cause a problem. I would probably secure the divider with a support going to the side on the right--the pressure of the water and sand will be significant, and could push too hard on it for just silicone to hold it in place.

For the connection between the 2--I would keep the hole as low as you can. I'd worry more about the pump going dry than an overflow situation. I'd probably go with a larger diamter pipe, too.

If you can position the pump so it's taking water from the opposite side from the skimmer, you should be okay. The bubbles are mostly kept inside the skimmer, so should not be a big problem.