sump design guidelines?

[WindowMaker]

Hi all, My current sump isnt cutting it anymore so I think I may build my own.

I will be either using a 29 long tank or build something similar design from acrylic.

Needs:
1.5" inlet from tank
2x filter sock + an emergency drain for the rare occasion where a filter sock may gum up.
bubble trap
constant water level section for skimmer.
refugium (maybe, I may just do this with a separate 10g tank)
outside tap for pump

I may add some extra bulkheads for future plumbing of addons as well. (reactors, fuge, etc...)

Any design guidelines out there that I should adhere to to be successful?

Thanks!

 

[uncleof6]

Only two I have heard of/recommend. To be of practical use, a "fuge" should be 10% of your system volume, (Arbitrary to a point, but gotta start somewhere,) and the return section should be large enough to allow the pump to run for several days, without running dry due to evaporation, regardless of whether you have an ATO or not.

 

[WindowMaker]

Your second point is the main reason I am upgrading, the sump starts to pull air after about 18-24 hours... no where near long enough.

 

[uncleof6]

Oh, and lest we forget, enough empty volume in the sump, to accommodate all the power out drain down, regardless of any other mechanical/electrical/passive, including siphon breaks, measures.

 

[WindowMaker]

Good call, my current sump can handle that, so I should be safe on that level.

 

[WindowMaker]

my current sump being about 15 gal max...

 

[ChemicalEdge]

If using acrylic dividers leave a fraction of a gap for expansion. Could crack ur tank otherwise. ( don't have them with a snug fit )

 

[uncleof6]

<a href="http://s655.photobucket.com/albums/uu274/uncleof6/?action=view&current=40breeder-1.jpg" target="_blank"><img src="http://i655.photobucket.com/albums/uu274/uncleof6/40breeder-1.jpg" border="0" alt="Photobucket"></a>

 

[WindowMaker]

I wish I knew how to use sketchup. that would be so much more fun than doodling on paper.

Good advice on the baffles, I didnt even think of that one. Ill try to get a rough sketch of what I was thinking up soon.

 

[av8rtrb]

If using acrylic dividers leave a fraction of a gap for expansion. Could crack ur tank otherwise. ( don't have them with a snug fit )

If you use acrylic dividers in a glass tank does regular aquarium silicone hold acrylic ok, or is there something better?

 

[rrasco]

If you use acrylic dividers in a glass tank does regular aquarium silicone hold acrylic ok, or is there something better?

Yes, regular silicone is fine. I'd recommend using GE Silicone I with a caulking gun, it's much nicer to your hands if you have a decent amount of silicone to lay down. I keep a smaller aquarium specific tube for those tight fit spots.

 

[uncleof6]

If you use acrylic dividers in a glass tank does regular aquarium silicone hold acrylic ok, or is there something better?

First, there is no such thing as "regular" aquarium silicone. The two products, one packaged by Aqueon, and the other packaged by DAP, labeled for aquarium use, are both repackaged products made by DOW, and the original packaging label says "not for use in aquariums." GE Silicone I, on the label says ~ "not for use in aquariums" so "regular aquarium silicone" is not an accurate statement. It is noteworthy to mention, that Silicone I is about the weakest formulation available.

Due to the surface properties of Acrylic, there is no silicone that bonds "well" with it. There are some silicones that are more tenacious than others, of course. Success with using silicone to secure acryllic baffles to glass can be accomplished, however the strength is no where near that of glass on glass, due to the material properties. So it really becomes a question of do you want something that is actually structurally sound, due to the material properties, or something that is just ok, due to the material properties.

 

[girlygears13]

Uncle, is there a certain silicone that you would recommend for bonding glass to acrylic? I vaguely remember some type of numbering system for silicone strength. This is making me even more nervous about not having glass dividers in my sump...

 

[uncleof6]

Uncle, is there a certain silicone that you would recommend for bonding glass to acrylic? I vaguely remember some type of numbering system for silicone strength. This is making me even more nervous about not having glass dividers in my sump...

The product, I believe you are looking for, is Dow 795. I "hear" that it is a bit more tenacious with acrylic.

There really is not a numbering system for silicone strength. What i can tell you, is that Silicone I is the weakest stuff around, and RTV100 series is the strongest stuff around, and arguably SCS1200, All made by Momentive (formerly GE.) Everything else, sorta falls in between.

I don't much smile on acrylic siliconed to glass for anything, save for corner overflow boxes and closely related applications. I have seen and heard tell of too many failures of such bonds, as well as the basic "instability" of acrylic in water (due to absorbing small amounts of water.) This does not mean that your baffles are going to fail. Even such a failure, would not necessarily be a catastrophe. Just a hassle i think should be, and definitely can be, avoided.

 

[girlygears13]

Cool thanks, looks like I'm ok, it's a very small sump, and if it falls...meh. If it ain't broke, don't fix it...