Using a Tunze 3155 for AWC?

[mike550]

Okay Newbie Q here. I have a 120G reefer and can’t set up a legit AWC because of location. So my process is usually drain 20G from DT and then refill. But I’m looking for a less disruptive way to do AWC. Would appreciate your thoughts on the following

I have a Tunze 3155 ATO on my system so thinking I could do a minor hack.

1. I take the ATO pump that’s sitting in my top off container and put in a container that contains fresh saltwater.
2. Using a small pump I take out tank water from the “filter” side of the sump.
3. Water level in the sump drops (does it?) and ATO triggers. ATO now puts in fresh saltwater.

Will this work?

Can the Tunze pump manage a longer pumping cycle?

Would it be better if I used a python or small pump and pulled out DT water instead?

Thanks in advance!

 

[JoshH]

Can I ask why you feel you can't set up a legit AWC? Many reefers have AWC tanks setup on the other end of there homes and just plumb the lines to the tank...

Your Tunze pump will time out after I think 8 minutes so however much water you're transferring will have to be done within that timeframe. I'm not sure how much GPM the pump pumps though so it might be doable...

Pumping water out from your DT will not trigger your ATO and it might not in your sump either if you're not pulling directly from the return pump section where the sensors are.

I would honestly suggest a small pump or siphon to get the water out and then a small pump to pump it back in and skipping the ATO pump altogether...

 

[mike550]

@JoshH -- Thanks for your reply and observations around the Tunze ATO. To answer your Q -- My RODI / Mixing station are in the basement and the display tank is on the main floor. I can't sneak lines to the tank as the basement below is finished. So re-plumbing becomes a real challenge. If I ran a hose the run would be around 40-80 feet and 16 feet vertical rise. So it's a lot of head pressure.

I was thinking that pumping water out of the sump would lower the level on the return pump side, but I might be wrong about that since there's a baffle (?) that maintains a specific water height for my skimmer.

 

[JoshH]

@JoshH -- Thanks for your reply and observations around the Tunze ATO. To answer your Q -- My RODI / Mixing station are in the basement and the display tank is on the main floor. I can't sneak lines to the tank as the basement below is finished. So re-plumbing becomes a real challenge. If I ran a hose the run would be around 40-80 feet and 16 feet vertical rise. So it's a lot of head pressure.

I was thinking that pumping water out of the sump would lower the level on the return pump side, but I might be wrong about that since there's a baffle (?) that maintains a specific water height for my skimmer.

If your system is running when you pull the water out as I mentioned previously your plan will absolutely work. But shutting the system down will prevent the ATO from kicking in as the baffle you mentioned will hold the water level full in the return section.

Honestly if it was me I would still hard plumb it but that's me lol

Another question, do you have a Manifold atall??

 

[qnguyen]

I am confused. Do you plan to be there to move the Tunze pump from the ATO container to the SW container? Or are you trying to set-up a true AWC (automatic water change without any interference from you)?

 

[mike550]

I am confused. Do you plan to be there to move the Tunze pump from the ATO container to the SW container? Or are you trying to set-up a true AWC (automatic water change without any interference from you)?

@qnguyen it is going to be manual. I will move the Tunze pump from the ATO container to the SW Container. Then use a small pump to draw water from the “filter side” of my sump. My hope or plan is that the ATO sensor will notice the change in water level and then add fresh SW to the system

 

[mike550]

If your system is running when you pull the water out as I mentioned previously your plan will absolutely work. But shutting the system down will prevent the ATO from kicking in as the baffle you mentioned will hold the water level full in the return section.

Honestly if it was me I would still hard plumb it but that's me lol

Another question, do you have a Manifold atall??

@JoshH yes I’d keep the system running. I don’t run a manifold on my return pump as it’s a DC pump so thats how I control flow.

I’m also thinking more about your suggestion of leaving the ATO alone and using a python to drain the DT and a pump with about 20 feet of head pressure to move water from the basement up to the DT OR two smaller pumps to drain and fill at the same time. Won’t be perfect but probably close.

 

[JoshH]

@JoshH yes I’d keep the system running. I don’t run a manifold on my return pump as it’s a DC pump so thats how I control flow.

I’m also thinking more about your suggestion of leaving the ATO alone and using a python to drain the DT and a pump with about 20 feet of head pressure to move water from the basement up to the DT OR two smaller pumps to drain and fill at the same time. Won’t be perfect but probably close.

I was going to say if you had a manifold run off a pump in the main part of your sump you could just hook a hose up to it and pump your sump dry down a drain. I had a similar setup, used a spare hose at the end of my manifold to pump my sump dry then used a pump to pump water from my buckets back into the sump.

 

[rvitko Verified Sponsor]

The controller limits the pump run time to 10 continuous minutes, 1.5- 3 gallons depending on pump speed setting and head pressure. I generally would not advise using this pump for this purpose. At the end of the day the pump is essentially a windshield washer pump and meant to run in short bursts, not more, I think the odds the pump will fail in a short time are high.