Differences in Tank After Setting Up Auto-Water Change (AWC)

[ca1ore]

Depends on your bioload, but I’d be surprised if 1% daily water change were enough to avoid much in the way of required nutrient export or mineral/trace additions. I moved to using the DOS for AWC about a year ago also. I don’t do as much per day as you propose, and in my case it was solely to reduce the drudgery of manual water changes. I still have to employ the same arsenal of nutrient export mechanisms and run my CaRx just about full out.

 

[BOWHUNTER4250]

I do automatic water changes as well ( approx. 30 gallons ) weekly on a 400 gallon ( twv ) with 2 small pumps and my Apex , very simple , very easy and have been doing this for over 3 years with no issues and i don't even need to be home . I also have the DOS however i only use this to dose Kalkwasser and when mine goes on the only noise i hear is when the pump head first kicks on ? other than that mine is very quiet ?

 

[Bramzor]

And what about te difference in water level before/after a change? I'm thinking about placing 2 sensors next to my ATO. One for low and high. Placed about 20% (of the water change) of the ATO sensor which is in my case about 1L so 6.64mm or 0.26inches above and below the ATO sensor. This most probably will allow me to detect any faults during the AWC when the change is off by 20% shortly after the change or even prevent from doing the change when ATO failed to work. Personally I would use 1 dosing pump with 2 heads, making sure that the volume is in theory identical.

But I wonder, did any of you ever test or had any failure?

 

[WallyB]

And what about te difference in water level before/after a change? I'm thinking about placing 2 sensors next to my ATO. One for low and high. Placed about 20% (of the water change) of the ATO sensor which is in my case about 1L so 6.64mm or 0.26inches above and below the ATO sensor. This most probably will allow me to detect any faults during the AWC when the change is off by 20% shortly after the change or even prevent from doing the change when ATO failed to work. Personally I would use 1 dosing pump with 2 heads, making sure that the volume is in theory identical.

But I wonder, did any of you ever test or had any failure?

Well I tried level sensors for my Water changer which does 3 tanks Daisy chained so each sump has an ATO.
Only One sensor on Each Water Changer.

I Tried (even with ATO sensor), (above) and (below ATO sensor) ....THE ATO is a (tunze osmolator with Level sensor and overfill sensor).

My ATO sensors were almost dead-on matched since I mounted them adjustable with magnetic holders. Was a bit tricky to get things perfectly matched (Playing with ATO). I however eventually everything was matched up.

After many weeks I sometimes got mis-matches for various reasons. Like moving stuff around (maintenance), adding/extracting water manually, etc. Impossible to keep matched up (ie ending water change refill on water change sensor to be perfect with ATO)

It never was a big difference (so maybe a tiny overfill, or tiny underfill).

At the end what worked best is Water changer level sensor is just below ATO sensor so it will always sense water. (Ie the float switch is raised), and when water change is done, (also Raised)

The logic is Water changer considers things a FAULT if it's float switch isn't raised (activated), meaning not enough water to start a water change.
The water changer also considers the Water Change successful if the Float Raises at end of water Change. Fault is not raised.

The ATO doesn't care, it just does it's job.

Since the Water changer is accurate enough, things are smooth and Water Changer only catches the Faults.

Water Changer cannot tell if Water Level is too high since it's sensor should always be raised. (except during water change) However the ATO overfill sensor does sense that, and Alarm goes off.