How to install baffles in 29g freshwater sump filter?

[Tom__in_Maryland]

How does one install baffles in 29g sump freshwater filter?  And what media to use in chambers?  please I know someone must know the best way to do this with a 29 gallon tank 30 x 18 x 12 .  Thank you in advance.

[MickS77]

I've never built a sump but I know baffles can be made of glass and siliconed into place. Media can something like the bags of bio-rings from aquarium co-op. 

[Andy's Fish Den]

Figure out what size the baffles need to be, go to a local glass shop or ace hardware and have glass cut, be sure to ask them to sand the edges, or get some acrylic cut instead and silicone in place. For media, usually first you have some sort of poly pads or filter socks to catch debris, then for biological filtration, you can use any of the ceramic medias available, pot scrubbies from the dollar store, bio-balls, lava rock. 

[gardenman]

Baffles are used to direct the water, but they don't have to be perfectly watertight, just strong enough to direct the water where you want it to go. That gives you some leeway in what to use. Glass and acrylic are the "normal" things to use. They're cheap and relatively easy to work with. In theory you could use bricks, or other block-type material to create baffles also. (Just be careful that what you use doesn't adversely affect your ph.

What you're trying to create with baffles is a path for the water to travel that optimizes contact with your biofiltering material. A typical set of baffles would have water coming in at one side, going through a mechanical filter media (socks typically) then down and under the first baffle and up through the first set of biofiltering material before overflowing the next baffle and down to a pump. (additional chambers can be added as needed.) Water tends to choose the path of least resistance though so very often the actual water movement will just be through a small part of your biofiltering material. The best way to overcome that is to use a fluidized bed type of biofilter using something like the K1 bio media and a powerful air pump to keep it circulating in the biofiltering chamber. 

Off the Deep End Aquatics on YouTube has a nice above tank sump with a fluidized bed section on one of his plywood tank builds housing his Arowanas and rays. His is above the tank rather than below the tank but it gives you a nice idea of how one should work.