Skimmer without ATO

[JW3571]

Do you guys recommend buying a skimmer if you can't have an ATO? From reading on here it sounds any skimmer that's in your sump is extremely sensitive to water level. I have to put about 6 quarts/day. I'd really like a skimmer but a ATO just won't work in my system.

[Jeff]

Some skimmers are better then others for an inconsistant water level. I had a Tunze Master Doc 9440 when I had my big tank and it self-leveled. Most skimmers will loose their foam head or overflow otherwise.

[Rich1427]

your skimmer should be in a chamber where the water level doesn't change your return pump should have its own chamber where it rises and lowers by itself but an ATO is highly recommended to keep salinity in check

[Misled]

Use baffles to control the level in the skimmer compartment.

[willy7499]

Use baffles as Misled said and have a large return pump section that can handle the evaporation between manual top offs.

[JW3571]

I guess I don't understand how the water level affects the skimmer. As long as their is enougH water that the pump can run, how does it overflow or lose its bubbles

[JW3571]

Anyone?

[willy7499]

I believe that it has to do with the differential pressure. Let's say that your skimmer is tuned to maintain a water level internally 12" above the water it is sitting in. If the water it is sitting in decreases by 1", the pump/output valve on the skimmer still wants to only maintain the 12" differential, thereby reducing the level in the skimmer. This would cause the skimmer to go out of tune and the water/bubble interface to change. Different designs in the skimmer and the pumps will make the overall unit more or less tolerant of the changes.

This is a simplified definition but explains the point.

[JW3571]

That helps me understand it a little more. Maybe I just won't be able to have a skimmer.

[The Punisher]

How is your sump set up? A lot of sumps are built with a skimmer section that has a constant water level. The return section of the sump is the area where you'll have fluctuating water level. I'm just curious but why can't you go with an ATO?

[sirreal63]

You could also use a recirculating skimmer, they are not sensitive to fluctuating water level.

[JW3571]

I have a 3 chamber sump. The first one is the where the water comes down from the overflow, 2nd is the fuge, and 3rd is the return where I have a submersible pump. I do have room in the return section but I don't think i have any room for an ato and i have no where to put a container.

What is a recirculating skimmer? How do they work?

[tkeracer619]

You can absolutely have an ATO.

All you need is a float valve and some small container mounted inside the stand. Gravity fed. It is pretty simple. Posting a pic will give us something to work with.


Skimmers require constant level because of head pressure and ease of pulling in air. As the water level changes the flow of water through the pump changes.

You can use an external skimmer but they also will fluctuate with different water levels. Not as much because air is not a factor but it still does effect it.

One way to get around this issue without an ATO is to feed the skimmer via your drain. You use a recirculating skimmer in your first chamber and run 100% of your drain into the input.

[The Punisher]

If your sump is set up like most then the section that your tank drains into will have a constant water level. You'll put the skimmer in this section so the ATO won't be necessary or really do anything as far as the skimmer is concerned. ATOs are nice to have though and don't take up much room at all.

[JW3571]

Here's a pic of my sump setup.

[JW3571]

Anyone?

[mojo~]

Honeslty, I would pull out the fuge and put the skimmer there. the skimmer, IMO, would be more important to run than a fuge. Unless you can run a large fuge it really isnt that great of a benefit. I havent run a fuge in years. Only a filter sock, gfo, carbon and a skimmer.

[The Punisher]

Honeslty, I would pull out the fuge and put the skimmer there. the skimmer, IMO, would be more important to run than a fuge. Unless you can run a large fuge it really isnt that great of a benefit. I havent run a fuge in years. Only a filter sock, gfo, carbon and a skimmer.

I agree with this. I just built my sump and went with a skimmer section and a return section, no fuge. It's a 40 breeder and I don't think I could have squeezed enough room out of it for a very effective fuge. My DT is a 120.

[JW3571]

I'd really like to keep the fuge since i've just set it up. If I can figure a way out to do an ATO could I put the skimmer in the return section

[andresp]

For a successful reef tank you definitely need a skimmer.

[moondoggy4]

How big is the tank? How about putting a HOB skimmer on it.