ATO & auto water change together

[Nimitz]

I'm currently downsizing from a large 200g system to a 60 cube. The 200g system has had a Genesis ATO & auto water changing system on it for years & has worked flawlessly. since I've had a stable system for years I haven't paid much attention to 'equipment' now I am again. I considering downsizing and simplifying. I'm considering going with the Tunze oscillator ATO since mt new sump has a ATO chamber built it and moving to one of teh dosing pump type water change solutions but there is something I don't understand ....

The Genesis system is designed with sensors that work together so that when an auto water change is triggered, the ATO system sensor suspends operation so you don't get the ATO system trying to replenish fresh water as the auto water system removes saltwater & lowers the sump level & they just fight eachother.

How do these other auto water change systems work where they don't also have an integrated ATO system as well? I must be missing something simple? Thx!

 

[RuuToo]

The dos has two metered pumps, and is removing the exact same volume of water that it is adding at the exact same time. It doesn’t change the water level at all. Any drop is filled by ato, just like normal.

 

[Joe31415]

I think a lot of people use an Apex to handle that. They can shut off the ATO while the AWC is running. I don't have an Apex. I have to Versa pumps, one in, one out, that both run for 2 hours. What I did is set them up so the one pumping water into the tank starts 15 minutes before the one pumping out of the tank. That keeps the AWC sensor under water during the majority of the time the water is being exchanged. During the last 15 minutes, when only the 'out' pump is running, the level goes back to where it should be.
This also makes it easy for me to make sure the pumps are still calibrated kinda sorta how they need to be. From time to time, I'll pull the plug on the ATO. If all goes as planned, when the AWC is done, the water level should be back where it started...just have to remember to plug it back in when I'm done.

I also had another thought. The Ranco temp controllers are widely used in the HVAC industry. My store has 5 or 6 of them controlling the temps in my coolers and freezers. I'm using two of them in my house currently (DT and reef QT). Another piece of HVAC equipment that I think would work well is a defrost timer. They're meant for coolers and freezers. They normally supply power to the compressor, but at set points throughout the day, for set amounts of time, they kill power to the compressor and send power to the defrost heater (melts the ice off the coils). This could probably be reused here. Have it send power to the ATO and then, say, once a day for an hour, it'll kill the ATO power and energize your AWC system.
I think that would work nicely, though my current set up (water pumping into tank starting earlier) means one less thing to break.

 

[Joe31415]

The dos has two metered pumps, and is removing the exact same volume of water that it is adding at the exact same time. It doesn’t change the water level at all. Any drop is filled by ato, just like normal.

But the problem, as I understand it, is that if one pump isn't calibrated correctly or otherwise isn't moving as much water it can be a problem. For example if you pump out 5 gallons and pump in 4.5, will replace the missing half gallon with fresh water and drive down the salinity.
I know people run into this problem with the Versa pumps when they have their saltwater bucket and waste bucket in the basement and pump water up and down to the first floor. If both the pumps are in the same place (instead of one by the tank and one by the saltwater bucket) the one pulling water further than it's pushing it often doesn't keep up.
Is that an issue with the DOS, since both pumps are essentially required to be in the same place?

 

[jsker]

As stated above, having a controller really helps with what you are looking to do.

I have a Apex controller and use a GHL Maxi for my auto water change. My auto water change is over three days period, my water level does not decrease enough for the ATO to kick in.

 

[jsker]

But the problem, as I understand it, is that if one pump isn't calibrated correctly or otherwise isn't moving as much water it can be a problem. For example if you pump out 5 gallons and pump in 4.5, will replace the missing half gallon with fresh water and drive down the salinity.
I know people run into this problem with the Versa pumps when they have their saltwater bucket and waste bucket in the basement and pump water up and down to the first floor. If both the pumps are in the same place (instead of one by the tank and one by the saltwater bucket) the one pulling water further than it's pushing it often doesn't keep up.
Is that an issue with the DOS, since both pumps are essentially required to be in the same place?

Apex sends a graduated cylinder to calibrate the DOS, done right the amount of difference is so slight that the salinity is not effected.

 

[Nimitz]

I'm assuming the location of the pump that removes the old water is in a different location within the sump than where the input for the new water is? otherwise if you're removing saltwater at the same time as adding new saltwater you could be essentially just changing the same water?

 

[Joe31415]

Apex sends a graduated cylinder to calibrate the DOS, done right the amount of difference is so slight that the salinity is not effected.

The versa does the same thing. But I imagine the calibration can drift as things wear out (rollers, tubing etc) or salt blocks one end or the other.
What I always wanted to do and maybe will do some day if I ever get a controller, is to, with the ATO off, pump out some amount of water, then pump new saltwater in until it trips a sensor, set to the same height, or using the same sensor, as the ATO.
Or, to avoid turning off the ATO, pump water in, then pump water out until the sensor 'un' trips.

 

[Joe31415]

I'm assuming the location of the pump that removes the old water is in a different location within the sump than where the input for the new water is? otherwise if you're removing saltwater at the same time as adding new saltwater you could be essentially just changing the same water?

Yes, I have mine set up such that it's removing water from the beginning of the sump (by the socks) and replacing it over by the return pump. I'm only changing a gallon a day on a 40-50gallon system. Technically some water that just went in will get pulled back out, but I can't be all that much since it has to travel to the return pump, through the DT, back to the sump and just happen to go right past the tube pulling water out, all while being diluted as it moves through the system.

Even just thinking about that sends me back to Diff Eq.

 

[RuuToo]

Technically you are probably correct, but if I calibrate my dos at the end of the drain line (which in my case is maybe 50 feet further away than the input) the difference is so slight that we’d be talking about a salinity change over the course of weeks or months.

frankly there are any number of other processes that can tweak salinity over time, and since I have a salinity probe that sort of mostly works, a digital refractometer and two manual refractometers, its unlikely to be that big of an issue.

Since I started doing auto water changes this way, I would literally never go back. Other techniques with multiple failsafes but more complexity are likely to be riskier IMHO, but to each their own.

 

[Joe31415]

Technically you are probably correct, but if I calibrate my dos at the end of the drain line (which in my case is maybe 50 feet further away than the input) the difference is so slight that we’d be talking about a salinity change over the course of weeks or months.

frankly there are any number of other processes that can tweak salinity over time, and since I have a salinity probe that sort of mostly works, a digital refractometer and two manual refractometers, its unlikely to be that big of an issue.

Since I started doing auto water changes this way, I would literally never go back. Other techniques with multiple failsafes but more complexity are likely to be riskier IMHO, but to each their own.

I agree. I was just bringing it up. It's certainly more of an issue when you're talking about a half gallon or gallon difference each day on a 50 gallon system then, say, a few hundred mls per day.

That was all certainly one of the advantages of a my freshwater tank. It didn't lose water anywhere near as fast as the saltwater tank. I'd be surprised if it lost even a half a gallon a week, where the saltwater tank (same size) is probably at least that much a day. Losing very little and being able to top it off with tap water made it pretty easy.
When it got low enough to need to be topped off (ie when the trickling water started annoying me), I could pull a gallon or two out and fill it all the way back up with water right from the sink.

 

[Nimitz]

Just found out Genesis is out of business. .... However since the system is working flawlessly I think I’ll just move the sensors and one pump to my new system. There should be enough room in my new sump. If it ever fails I’ll look at the do’s system but I don’t see the need to spend $500 on a system when the one I have is working perfectly. Bedsides I really need to get going on ordering my new Atari Tempest arcade game to go next to the Atari Area 51/S4 game I already have

 

[Joe31415]

I don’t see the need to spend $500 on a system when the one I have is working perfectly.

$800. The cheapest way, as far as I've been able to tell, to get a DOS up and running is to spend $800. The DOS is $300 and the ApexEL (brain, energy bar, two probes) is $500. But now that I think about it, I think the ApexEL was a limited time thing. It does appear that BRS is out of stock on it. So you'd have to get a brain for $400 and an energy bar for $280. That's $980, just to run two pumps.
That's why I waited so long for the Versa pumps to be back in stock. I just couldn't bring myself to spend that much money on that system. At least not right now maybe someday, but not today.

 

[laverda]

Search for the Kamoer X2S set up. They are on sale on Facebook for $170 now. It sounds like it will do it all at a very reasonable price and the reviews have been good. There is no way I will trust AWC or ATO to Apex and dos with out some redundancy added in for when it fails!

 

[Tuffloud1]

I’ve been running a Neptune DOS for auto water changes for the last 6 years with no issue whatsoever. I calibrate after I run my lines where they will be permanently.