DIY sump design
I am contemplating DIY sump design for a freshwater tank. the tank is a 75 gallon tank. I have a 35 gallon (36x12x18 LWH) which is about to be upgraded, and i plan to convert the 35 gallon into a sump. The main tank will be planted, and I will have injected CO2, for which I hope t make an inline reactor (I'll probably post that design with questions later :p). This is my first attempt at DIY anyting for my tanks, and my first experience with a sump.
i have a pump which outputs about 360 GPH. It is actually a replacement pump from a red sea reef system. I tested the GPH by pumping 4 gallons and doing the math. As a side not, I may be able to trade it for a rio 2500 pump (which I believe for over 700 GPH).
The baffles are 12 inches, with the raised baffles 2 inches from the floor. Water level would be at about 13 inches. My design has a 6 inch entrance chamber, a baffle allowing water flow over, a filtration chamber, a "refugium" for plants, and a pump output chamber. I attached a deign schematic.
I may place scrubber sponges in the entrance chamber. I also plan to use a filter sock.
The filtration chamber is 6 inches long (and 12 deep, the tank depth) and will start with a sponge for additional mechanical filtration, followed by biological filtration consisting of ceramic disks (such as Fluval Biomax), and at the bottom smooth river stones (around 1-2 inch) with lots of room for water flow around them.
The "refugum" wil have some fast growing stem plants and frogbit, as nitrate sucks. I realize this may not be necessary on a planted tank, but more plants means more nitrate reduction, and cleaner water. I will also densely plant is to allow more surface for biological filtration.
One alternate option is to separate the refugium a bit from the main flow by making a separate square chamber with holes in the glass to allow water ti only flow in and out at a slower rate, as to much flow is bad for the plants.
Finally the pump chamber is about 6 inches, with the pump raised as an extra precaution against floods. That was only so much of the sump water can be pumped into the main tank in the case of a failure in the overflow.
I would like any comments on this design, as I frankly don't know what i am doing. I have some specific questions:
1. Is 360 GPH enough? I have hard a hard time finding info on appropriate flow rates in freshwater sumps.
2. Is 6x12 inches an adequate size for the filtration media chamber?
3. Is the filter media OK? Should I use something else, like filter floss (with which I have no experience), or anything?
Any other comments or constructive criticism are welcomed.