Sump Help

Alright i got a free 20g tall. I was planning on making it into an sump for my 75 gallon. Alright the 20g is 24/12/16(l/w/h). What would be a good return pump and Gph rate for this setup? Anyways I was going to make 4 chambers. 1. 6" witch will have pipe from over flow box and Ls/LR. 2. 10" For Skimmer. 3. Bubble Trap area witch will be like a total of 2 inches. 4. 5" for the return pump.
Little Pic to show you idea. OH and please add on any thing, im a big newb and this is my first diy project, so i need as much info as possible Thanks!.

 

That sounds OK, although I think most people usually put the skimmer in the same section as the pipe from their overflow and then put the LS and LR, sometimes macroalgae, in the second chamber, this is considered the "refugium" section mostly, then the return section last.
You'll probably get a lot of turbulence from your overflow pipe which will stir up the sand quite a bit which is why I think most people put it after the skimmer/overflow pipe section.

Also you might want to reconsider the size of your return section, this is where all of your evaporation will show up, you probably want to make sure you have a decent volume of water in there so that your pump doesn't run dry if topoff water doesn't come for a day or two in an emergency.

GPH on a 75 I would go for about 400 personally (after head loss from plumbing) that will turn your tank's volume over through the sump 5 times an hour.

Here's a ton more info on sumps.

Melevsreef.com - What is a Sump?
Everything You Always Wanted to Know About Sumps, Part I by Greg Taylor - Reefkeeping.com

 

I don’t like sand in section 1 where the tank water is pouring in, will probably not stay put for you and is not needed in a fast moving sump anyway – there is enough in your tank.

GPH pump – depends on your tanks overflow and what it can handle, not a good idea to pump 1500 GPH into a tank that can only drain 600 GPH

I like the skimmer in 2, that way no air bubbles messing up the skimmer pump (if you were to place it in one I’ll assume the drains are going to cause plenty of air bubbles).

 

I think you are going to need a larger return section to handle evap.

If your water is 12 inches deep in that return section you will only have a total of 2.8 gallons of water in there. So you will only be able to evaporate a gallon or so before your return pump starts sucking air bubbles.

So do what you can to make your return larger. Remove the section with rock/sand and put the skimmer there, then use an eggcrate baffle to separate a chaeto area from your return pump. The chaeto will trap all the bubbles, and you will have more water available to evap since the fuge and return will share the same water.

Kim

 

Hey Validity,
I have a sump that I just finished a couple weeks ago from a 20G tank. Here is a diagrams that I drew up, but they're not perfect dimensions, so I reccomend you do some measureing yourself and make sure you have the right dimensions for your needs. I chose my design so that I could maximize the amount of water volume. I built mine around my protein skimmer, a DSB, and an eheim 1250 pump. I also purchased cut glass from a glass/window shop for around $55. Don't use acrylic since it doesn't bond with glass when using silicon. Honestly, i felt the glass was cheaper than buying acrylic and having to cut it myself, ect ect. Just buy some aquarium safe silicon at home depot or lowes and it'll hold very strong. With my 46 gallon, this sump is perfect, but with your 75gallon tank, my dimensions may not work for you since if a power outage occurs, your sump may overflow since you'll have more water draining to it from the main tank. IMHO, i reccomend the biggest sump you can fit in your stand. Again, use my dimensions as a reference and get an auto fresh water top-off. With an auto top-off, you can make your return smaller and not having to worry about evaporation as much. Good luck and hope to see pictures of your setup soon.