Resevoir size effect ATO siphoning?

Hey all,

Got a Tunze 3155 Osmolator and am eager to set it up. I am torn between two reservoirs, which are very different in size. I have no experience with ATO's and am wondering if the size of my reservoir will impact the possible siphoning of the resevoir into my sump and disaster? Everything I've read has said the resevoir should be lower than where it is pumping into, but I don't get how to do that, since most would pump into their sump in their stand (which would be close to the ground).

Here are two pics that illustrate the different sizes of resevoirs I'm looking at and the Tunze tube will be positioned over my return in my sump.

Let me know if you had any thoughts/advice on which to get and what I could do to not worry about possible siphoning.

Thanks!

Tall and skinny resevoir:




Short & wide resevoir:

 

I could be wrong about this, but... and the more i think about it the more i think that i COULD be wrong... if your pump for the ato is sitting in the bottom of your resevoir, and the end of your tubing from your res. into your sump is higher than your pump is, you should be okay? If thats not true then i would just say as long as the end of the tubing from your ato is above the water level in your resevoir, then you'll be ok. anybody else?

 

The ato uses a dosing pump. It does not start a siphon. I have had my bucket well Above the sump with no siphon starting. As soon as the pump turns off so does the flow.

 

Ya, you can't have the tube hanging down into the sump. the end of the tube can not be lower than the highest level in your reservoir. It will siphon.My reservoir was tall and I just ran the tube along the top of the sump and let it dump in. My sump was high and I used one of those blue 7 gal camping jugs. Regardless of what you have, you have to have the tube right.

 

woops.

 

Haha thanks for the replies guys, but I'm still kinda confused. I keep reading things specific to the tunze 3155 of siphoning happening related to the reservoir and top off area heights.

 

Yes, the Tunze is just a regular pump and it will siphon. Whether or not one does or doesn't is different... there is nothing preventing the Tunze pump from siphoning and it must be guarded against. Follow the directions.

In your drawing why is there a box around the sump? Do you have to get up and over this?

You just have to keep the end of the tube higher than or equal to the height of the reservoir level. If for some reason it has to drop a distance and you don't want it splashing and making noise, you can just drop it in a small funnel... get a little funnel, put a little bigger piece of tube for it and drop that down to the level in the sump. No noise, splash or siphon. Or just position the hose to where it runs down the pane of glass for the sump, down the side of it.

 

Thanks for the info PMan, my sump is just your run of the mill one, no box around it, I just was lazy with the diagram.

When you say "You just have to keep the end of the tube higher than or equal to the height of the reservoir level" I'm thinking it would be impossible with the taller reservoir. as I will be filling it with 20g of RO/DI and at that level it will be hard to get the tube higher than that as I can't go much higher than the ceiling of my stand. Am I making any sense

 

Is it possible to add a check valve?

Edit: Nvm That only stops the reverse flow

 

Keep the tubing at any level you want...just make sure the end that will deliver the water is NOT submerged. This will cause the water to stop flowing when the pump is de-energized. If the tubing is submerged, it will back siphon, causing a whole lotta bad.