Gravity driven scimmer and sump
 

Can I use gravity to drive my water flow through my scimmer and into my sump/refuge, using a pump to return the final product back to my main tank?

Below is a diagram

[IMG]http://reefcentral.com/gallery/data/500/176649scimmer.GIF[/IMG]

1. Overflow from main tank
2. scimmer
3. bubble trap/sump
4. refuge
5. return
6. return pump

Is it possible to use gravity to drive the flow through the scimmer and into the refuge if the height of the scimmers output is below the input into the tank but above the the main tank overflow? I am currently not sure it would work, would I need to raise the scimmers output to higher than the sump? Or would the flow continue as long as the input and water line inside the scimmer are above the waterline inside the sump?

I am setting up a tank with a gravity fed skimmer and from what I've read and been told it will only work with a recirculating skimmer.

Yes you can, but most people find that useing gravity to feed the skimmer does not work very well, you get extra bubbles, which screw up the skimmer plus the flow is not exactly the same all of the time, so it can be hard to keep the skimmer adjusted.

But other than that it will work.

Kim

then i guess ill just sit a scimmer in the sump and attach a small feeding pump to it. I am planning on making this kind of scimmer:

[url]http://www.hawkfish.org/snailman/diy6inskimmer.htm[/url]

I am hoping to have one air pump drive the scimmer and some air stones in the refuge. And to have the main sump and scimmer all run with just one pump. Is it possible to move the scimmer to the other side of the setup and set it to scim the output from the sump/refuge instead on the return route to the tank?

After that, im using several other pumps to run closed loops with inline UV and carbon filters to keep up the waterflow without using powerheads.

i realize the drawing is not to scale...but just so you know the way you have it drawn it will overflow your skimmer...the output pipe cant be taller then the skimmer...other wise the water level will be above the skimmer...

Yep, was due to not being to scale, but thanks for pointing that out :D Am new to the hobby and that could have been a mistake I carried over by accident.

[IMG]http://reefcentral.com/gallery/data/500/176649better_diagram.GIF[/IMG]

Thats a better diagram with more details.

1. overflow from tank
2. scimmer collection cup and cup drain line
3. main scimmer chamber
4. scimmer output
5. bubblemaker
6. bubble trap
7. baffles to slow water speed for refuge
8. refuge

With this better drawing, with more clear details, do you think this design would work with a gravity feed input?

I have an ASM mini G and just set it up in a similar fashion. Re-circ mod with the feed from my overflow. The flow is definitley hard to control and there are "extra bubbles", however it's producing much more skimate then ever before. I'm going to try a gate mod valve and maybe putting a valve from the overflow to see if I can keep the flow a little more consistant.

Good luck on your project.

I'd re-think your diy skimmer. If you want to gravity feed a recirc euro style or deltec style is really going to be your best bet.

Here's a link to the 6"er I built.

[url]http://archive.reefcentral.com/forums/showthread.php?s=&threadid=1044448[/url]

[QUOTE][i]<a href=showthread.php?s=&postid=11574335#post11574335 target=_blank>Originally posted</a> by kgross [/i]
[B]Yes you can, but most people find that useing gravity to feed the skimmer does not work very well, you get extra bubbles, which screw up the skimmer plus the flow is not exactly the same all of the time, so it can be hard to keep the skimmer adjusted.

But other than that it will work.

Kim [/B][/QUOTE]

If you set it up right, you can have 100% of your overflow water going into the skimmer and no bubbles. Click on my little red house to see more, but the short version is that if you use a 'dual standpipe' method, you run your primary drain into the skimmer. No bubbles.

The only thing to watch out for is DO NOT use a standpipe with a gate valve on it if you are going with direct feed. Use a telescoping standpipe instead... much more forgiving with water flow flux, which you will have when you direct feed like that.

you do not want to put all your overflow water through your skimmer just 1-1.5 times your water volume per hour. so just tee off the overflow tube and put a small ball valve to adjust the flow through the skimmer. works great and saves you from using another pump to feed the skimmer.

My overflow rate is just 1.5x the tank volume per hour...lol... so I run it ALL through. Really, 1.5-2x is all you ever need for an entire sump's flow anyways.

Harold

Why would you not want to put all of your water through t he skimmer?
We put surface skimmers in our tanks to concentrate the surfactants, and then move to them to the sump. Should we not try to maximize our skimming by feeding this concentrated stuff into our skimmers, verses just mixing it all back up and hoping we catch it the next time around?

Kim

so what you are saying is, with a 90-110g tank and a 30f sump, id only be looking to run about 1.5 x that through my scimmer every hour? if the flow is so little...id consider putting the scimmer on its own closed loop at the back of the tank with a small motor to drive it and keeping the water level inside the sump identical to the water level of the tank.

And I am really interested in building most of this stuff, as its a nice way of saving money and also helps sway the wife...$300+ for a store bought scimmer, or 100 or less for my own...and with my own I know how it works, how to repair, everything.

This is the scimmer im going to make (with a little modification):

[url]http://www.hawkfish.org/snailman/diy6inskimmer.htm[/url]

I plan on using a device called a bubble disk that is great at making an obscene amount of small bubbles and is about 5.5in across...fitting perfectly in the tube. The pump that powers it will also feed a couple of aerators in the refuge, as I am planning on displaying part of that tank too.

If only about 160g needs to get to this every hour, im going to figure out a way to get that out of the tank without adding a bunch of extra showing pipes in the tank.

[QUOTE][i]<a href=showthread.php?s=&postid=11577310#post11577310 target=_blank>Originally posted</a> by kgross [/i]
[B]Harold

Why would you not want to put all of your water through t he skimmer?
We put surface skimmers in our tanks to concentrate the surfactants, and then move to them to the sump. Should we not try to maximize our skimming by feeding this concentrated stuff into our skimmers, verses just mixing it all back up and hoping we catch it the next time around?

Kim [/B][/QUOTE]


That was my thinking, why not pass all of the flow I can through the scimmer, refuge and then send it back into the tank? It seems like overcleaning the water is better than just cleaning it enough.

[QUOTE][i]<a href=showthread.php?s=&postid=11577310#post11577310 target=_blank>Originally posted</a> by kgross [/i]
[B]Harold

Why would you not want to put all of your water through t he skimmer?
We put surface skimmers in our tanks to concentrate the surfactants, and then move to them to the sump. Should we not try to maximize our skimming by feeding this concentrated stuff into our skimmers, verses just mixing it all back up and hoping we catch it the next time around?

Kim [/B][/QUOTE] If this is for a recirculating skimmer all you want is 1-1.5 tank and sump volume per hour. so if you have a 100 system you want 100-150 gph through the skimmer per hour. just about any manufacture of recirculating skimmer will recommend this. most recirculating skimmers cannot proses all the water coming from you overflow.
if you are building a air driven skimmer I am not for sure but I would thank it would be the same 1-1.5 vph
if you put all the water through the skimmer it would cause to much turbulence in the skimmer body. making you skimmer less efficient

I just built an 8" diy skimmer and have it gravity fed and it's rocking the caspah on my 90 gallon. No cyano or flatworms after 2 days and the water clarity couldn't be clearer. I went old school and put a U upside down in my internal overflow with 1" PVC and connected it to a 3/4" nylon tubing via a threaded barb. It runs to my skimmer which is on the side of my tank and I have a ball valve before the skimmer to control flow (this also helps because when I do water changes/clean the tank I just cut the ball valve and it stops the suction, when I turn it back full it starts it again). This way I still get surface residue from the overflow but all the water isn't running through my skimmer (would be about 500GPH and IME high flow through skimmer causes inefficiency and problems) and the rest flows into my sump/fuge. I have no problems with bubbles because it never sucks up air and the flow is always constant. Also...if you put a hole right below the surface then no matter how far down the pipe goes, once it reaches the hole it cuts the suction. Of course pictures speak a thousand words so if you interested in my set up just tell me. It is by far the most convenient set up I've had.

I am interested in everything, this is my first tank and im plunging in at the deep end building the sump, refuge, scimmer, gravity powered auto top up, and closed loops all from scratch. i only plan on purchasing the tank, LR, pumps, stock and sand. Everything else will be hand built using whatever knowledge I learn from here.

Id attempt to build a tank, but it seems to me that having a seal fail and an entire panel give out is not something I want to play with, not when it involves over 100g of water and several thousand dollars worth of perishable stock.

So yes, any diagrams you can show me of your setup and a quick explanation of how the device works would be greatly appreciated. Also, and mods you can explain for pumps or anything else similar is also greatly appreciated.

If you want to run more flow through a skimmer(spelled with a K), look into a Beckett or Downdraft skimmer. AESS and Aqua C make some nice ones as well as others. I had my skimmer fed by the return when I first set up the tank, it was a royal PITA to get the flow adjusted right and it was always changing. With a recirculating skimmer, you have to either run a T of the main drain or run 2 drains. I think with the T it would be a lot easier to get it to be consistant. Good luck though.

Hey, I saw this scimmer, and wonder if its a viable alternative, It seems like air is fed into the pump along with the water and then fed into the scimmer, once there the air rises, the water flows over and then out of the scimmer...It seems like a relatively simply design requiring only 1 pump to overate everything except the air. Could sit something like this in the sump and have it pump out to the refuge or back into the sump. And it looks real easy to build too.

[url]http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4392+7928&pcatid=7928[/url]


forgot the link.