18"x12"x12" Sump

[Allen]

Is this an acceptable size for a sump for a 30 gallon tank ?

 

[ox5477]

I think I've heard the rule is you want the sump to be atleast 30 to 40% the volume of your tank.

18x12x12 = 11.2G

So thats about 35% of your tank volume so your good

 

[andywg]

I think I've heard the rule is you want the sump to be atleast 30 to 40% the volume of your tank.

18x12x12 = 11.2G

So thats about 35% of your tank volume so your good

That is a bit much. Going by that I would want somewhere around 45 to 60 gallons on my 6x2x2 tank, whereas I have 28 and this is more than enough.

More often quoted is that you want to aim for around 10% of the display volume in bio-media.

 

[SkiFletch]

There's no science in designing sumps. Make it as big as you can make it and still have it serviceable IMO

 

[Allen]

OK, I have got a 24" x 15" x 18" sump that I now need to divide up.

I want something like this

Inlet chamber/skimmer one end, into area with live rock/sand, into bubble traps, into return area for pump.

Anyone got any recomendations for dimensions, or just get some dividers and whack them in ?

 

[andywg]

As the sump is comparatively quite small, I would want a fair amount (around a third) dedicated to the return pump chamber, otherwise you may find yourself having to top off far more often than you want.

The first chamber I would just make big enough to get the skimmer in and then use any other space left over for the LR.

 

[Allen]

As the sump is comparatively quite small, I would want a fair amount (around a third) dedicated to the return pump chamber, otherwise you may find yourself having to top off far more often than you want.


Why does the size of the return chamber affect top off ?

 

[SkiFletch]

Sounds like a 20 long, why not do what melev did with his 20 long sump

 

[andywg]

Why does the size of the return chamber affect top off ?

In a sump system the first part that actually lowers in level is the return pump reservoir. If the reservoir is too small then that level will drop very fast during the day and you may find yourself topping off the tank every day.

 

[Allen]

is that level dropping in the return resevoir due to evaporation ?

If its evaporation, surely surface area being smaller would be better ?

Or am I missing the point here

is that level dropping in the return resevoir due to evaporation ?

If its evaporation, surely surface area being smaller would be better ?

Or am I missing the point here

 

[andywg]

is that level dropping in the return resevoir due to evaporation ?

If its evaporation, surely surface area being smaller would be better ?

Or am I missing the point here

The evaporation will take place across all the surface area of the system. However, due to the way the water flows through the system and the sumps the chamber which will drop in level will be the return chamber as this is the lowest point of the system (water flows into other chambers until it hits the top of a baffle and spills into the next chamber).