Single Neptune DOS Auto Water Change for two aquariums?

[Patrick Cox]

I have a Neptune DOS setup in my fish room that is connected to my main display in the next room to perform auto water changes. I also have a QT tank in the fish room that I was thinking about hooking up to the same DOS with tube dividers and inline valves so I could choose which aquarium I wanted to perform a change on. So I would open the valves for one tank and close on the other and just let the auto water change run. Any concerns with this?

Thanks!

 

[Reefing Madness]

 

[Patrick Cox]

Thanks! Glad someone else is interested!

 

[TL1]

The calibration for each tank would likely be different... You'd still be changing some volume of water close to what you desire, but if it's important for you to be precise, then I would consider another approach.

Making sure there isn't any air trapped in the fittings on the suction side could be a challenge. Also, there's risk of user error (wrong valves open/closed).

Maybe someone on here has done it before? You may just have to set it up and play with it, but it seems like it wouldn't work on paper.

 

[Sisterlimonpot]

If you wanted to automate it, you can use pinch valves or some sort of motorized ball valve.

But the crucial part as @TL1 pointpointed out is that you can only save 1 calibrarion for each pump.

Not sure if that's a deal breaker, depending the size of the tanks, a slight inaccuracy in calibration may not be such a big deal.

 

[Patrick Cox]

If you wanted to automate it, you can use pinch valves or some sort of motorized ball valve.

But the crucial part as @TL1 pointpointed out is that you can only save 1 calibrarion for each pump.

Not sure if that's a deal breaker, depending the size of the tanks, a slight inaccuracy in calibration may not be such a big deal.

Thanks for your replies. These are good things to consider. One thing I don’t follow is why the calibration would be affected. However I don’t think I care as long as the remove equals the add. Thanks!

 

[Patrick Cox]

The calibration for each tank would likely be different... You'd still be changing some volume of water close to what you desire, but if it's important for you to be precise, then I would consider another approach.

Making sure there isn't any air trapped in the fittings on the suction side could be a challenge. Also, there's risk of user error (wrong valves open/closed).

Maybe someone on here has done it before? You may just have to set it up and play with it, but it seems like it wouldn't work on paper.

Thanks! Meant to include you in my reply above.

 

[Sisterlimonpot]

One thing I don’t follow is why the calibration would be affected.

It's always recommended to calibrate a peristaltic pump in the configuration you intend to use it.

For instance, the outlet hose may be 3' and the inlet 10'. That configuration effects calibration based on it's particular physical restriction and how the deformation of the peristaltic tube effects flow when the rotor acts upon it.

Differing the lengths and number of bends changes how the tube acts thus [sometimes] greatly changing how much fluid flows based on 1 revolution of the rotor.

This is why 2 side by side peristaltic pumps sitting next to each other can be pumping the same amount of fluid, but if atmospheric pressure presses harder on one peristaltic tube more based on restrictions inside the lines, the pumps are going to be moving at different speeds.

However I don’t think I care as long as the remove equals the add. Thanks!

That's why you should at least be aware. Unless the pumps are calibrated to compensate for these physical restrictions you're not going to get equal amounts out of each pump.

In your situation, you would have to calibrate to one configuration, and then try to match the fluid flow in the 2nd configuration by manipulating the restrictions to match the 1st configuration.

OR, don't get that far into the weeds and just have fun. But know that you're going to have to monitor sanity and make slight corrections from time to time.

 

[A_Blind_Reefer]

eh, you could do it. There’s always a way. By the time you plumbed it up with all the valves and everything (especially if automated with solenoids or ball valve actuators) you’d probably have spent enough to justify buying another dos. As far as concern goes, if it were two different display tanks I really wouldn’t have any. However, if it’s a medicated qt tank I would make sure that there would be no chance of a siphon effect should something go wrong if I had anything in the display (like inverts) that couldn’t handle certain qt treatments. If it’s not medicated, I’d still take steps to ensure one tank couldn’t back siphon to the other if something went wrong just to prevent an overfill or something.

 

[Patrick Cox]

It's always recommended to calibrate a peristaltic pump in the configuration you intend to use it.

For instance, the outlet hose may be 3' and the inlet 10'. That configuration effects calibration based on it's particular physical restriction and how the deformation of the peristaltic tube effects flow when the rotor acts upon it.

Differing the lengths and number of bends changes how the tube acts thus [sometimes] greatly changing how much fluid flows based on 1 revolution of the rotor.

This is why 2 side by side peristaltic pumps sitting next to each other can be pumping the same amount of fluid, but if atmospheric pressure presses harder on one peristaltic tube more based on restrictions inside the lines, the pumps are going to be moving at different speeds.



That's why you should at least be aware. Unless the pumps are calibrated to compensate for these physical restrictions you're not going to get equal amounts out of each pump.

In your situation, you would have to calibrate to one configuration, and then try to match the fluid flow in the 2nd configuration by manipulating the restrictions to match the 1st configuration.

OR, don't get that far into the weeds and just have fun. But know that you're going to have to monitor sanity and make slight corrections from time to time.

Thanks. This was helpful.

 

[Moonraker76]

I was wondering if it would be possible to use the same salt water vat to do AWC on three tanks - but would use three seperate pumps to do it. As I'm GHL that would be three Doser 2.2 Maxi pumps. But not sure if that would just be too lazy (and obviously this is not including a medicated tank - DT, a coral only tank and an invert only tank).

 

[Sisterlimonpot]

I was wondering if it would be possible to use the same salt water vat to do AWC on three tanks - but would use three seperate pumps to do it. As I'm GHL that would be three Doser 2.2 Maxi pumps. But not sure if that would just be too lazy (and obviously this is not including a medicated tank - DT, a coral only tank and an invert only tank).

If I'm not mistaken, you're suggesting 4 pumps. One to move NSW to tank A, one pump to move water from tank A to tank B and so on. Pump 4 will move water from tank C to the drain??

If so, that is done by quite a few hobbyist. I know a 3 locally that do something similar. The biggest concern would be pump accuracy. In order to not have salinity creep, you're going to want to calibrate the pumps more often and watch salinity in each tank a bit closer.

 

[Moonraker76]

If I'm not mistaken, you're suggesting 4 pumps. One to move NSW to tank A, one pump to move water from tank A to tank B and so on. Pump 4 will move water from tank C to the drain??

If so, that is done by quite a few hobbyist. I know a 3 locally that do something similar. The biggest concern would be pump accuracy. In order to not have salinity creep, you're going to want to calibrate the pumps more often and watch salinity in each tank a bit closer.

I wasn't really thinking that way as wanted to keep the three systems separate. So:

#1 2.2 Maxi Pump moves fresh saltwater to Tank A and empties to drain.
#2 2.2 Maxi Pump moves fresh saltwater to Tank B and empties to drain.
#3 2.2 Maxi Pump moves fresh saltwater to Tank C and empties to drain.

I'm just not sure whether plumbing three separate pumps into the (500-600 litre) fresh saltwater container wouldn't be asking for trouble.

 

[Sisterlimonpot]

I'm just not sure whether plumbing three separate pumps into the (500-600 litre) fresh saltwater container wouldn't be asking for trouble.

What's your primary concern?

 

[Moonraker76]

What's your primary concern?

Whether putting that many lines into the Saltwater vat would work. There is also a couple of QT tanks so I guess if three would work five would?

Then it would come down to volume but I'd just have to stay on top of that.

Then it's finding someone to fix it up for me. The plan is having a company design and install the tanks as I'm not the greatest at plumbing side of things (I have converted my garage into a Fish room and the main DT tank will go in the wall between the garage and the living room directly behind it.) And hopefully they can fix up up the RODI/mixing station and AWC side of it as well.

Lots of theories and ideas at the moment before thinking of implementation.

 

[Sisterlimonpot]

Ahh I see, the only difference between 1 or 3 tubes pulling from the same vat is going to be how much more often you're going to have to mix saltwater.

In fact a great benefit to your idea is that all 3 tanks will be getting the same salt mix so the salinity will be consistent in all of them.

 

[areefer01]

You could use the LLS modules as one option. This way you can do things based on water level(s). As mentioned by a few the calibration could throw things off unless you have run all lines exactly the same. This way you run a calibration the device wouldn't know Bob from Sally.

In any case the LLS (liquid level sensor) could work. Just add in some redundancy and Bob is your Uncle.