Sump Questions

[dayzofspeed]

is there a minimum size i should be aware of, i have a 240l tank? i have a small tank for my sump, much smaller than i anticipated @ only 25l - 60cm 20cm x 20cm will this be totally unusable?
i was planning originally going with a twin diy overflow pipe system 32mm out 25mm return, would i need to reduce this to a single do you think?
my return pump is 3000 lph i am worried that i will be emptying the sump quicker than it will fill or that the flow through it is going too be turbulent in such a small sump.
also i was planning a deep sand bed refugium but with a tank at only 20cm high i am thinking this is unworkable.
i am also concerned that such a shallow sump is going to be setting myself up for flooding problems should i suffer a powercut

can anyone give me some advice on this as i think i've almost talked myself out of using it

 

[-Nemo-]

In terms of sump size, bigger is always better. Whether the one you plan to use is too small, has to do with what you're already thinking about. If it's too small to fit equipment or what you want, you might considering getting a larger sump. As per the flooding problem, there's always ways to set up a sump and tank to prevent flooding from power loss. The only problem is the water level in the sump is going to be lower, resulting in less water volume overall.