Question about simple auto water change system

[MoshJosh]

Would this work?

tank with new saltwater + an air stone

A pump on a timer that runs a few minutes a day

an overflow in sump that runs to a drain or waist water tank

pump would turn on and pump water from the new saltwater tank into the displays, old water would overflow out of the sump into a drain. . .

???

what other things to consider???

 

[srit1]

Yes that will work as long as you are also accounting for evaporation. Run your ATO continuously or often, turn it off for a few minutes when you then run your AWC pump.

Another thing to consider, any time you stick your arm or a new rock or anything into your system, you will overflow water into your drain, so you may want a way to close that overflow for such times.

 

[MoshJosh]

Yes that will work as long as you are also accounting for evaporation. Run your ATO continuously or often, turn it off for a few minutes when you then run your AWC pump.

Another thing to consider, any time you stick your arm or a new rock or anything into your system, you will overflow water into your drain, so you may want a way to close that overflow for such times.

That’s a good point! I didn’t even think about water displacement then putting hands in the tank! Such thing as an electrically controlled valve that I could put on the same timer as the pump?

 

[jsker]

Would you happen to have a controller?

Things to consider. With pump turning on and off twice a day, make sure the amount going in is the same amount coming out of the system.

You will need two pumps working at the same time in the sump. One for waste water by the skimmer and one for the new saltwater going in to the chamber by the return pump. This method will give a truer water change, without pumping the new water out.

If you have a controller, I would suggest a DOS or a GHL Maxi. With the GHL Maxi one does not need a controller. All I do is mix my salt in a reservoir, and let the pump do the rest. My waste water line goes directly outside, there is no buckets too empty.

I was in Grand Junction 3 months ago, traveling through.

 

[n2585722]

The thing about the overflow was already mentioned where every time you stick your hand in your tank you will loose saltwater and it will be replaced with top off water instead. I do AWC with three pumps if you include the top off pump. All three are dosing pumps since my top off and fresh saltwater storage is in the garage. The tank is 35ft away form the garage. The drain used is about 20ft away. The water lines between are 1/4" like what is used with RODI systems. To begin with I used two pumps with AWC that had a matched flow rate. I wasted some fresh saltwater getting them matched. I then switched to a dual head pump. That worked ok but I decided to try the built in auto water change regimen in my controller so I am back to separate pumps. Since ATO and AWC are controlled inside the regimen the ATO s automatically disabled during the drain and fill operation. The drain pump runs for 11 minutes. Then the fill pump runs until the full sensor is made. It uses the same sensor as the ATO. There is a option to drain to a low sensor in the regimen but I just time it since I am using a dosing pump. This is done 3 times a day for around a total volume of 1000ml a day in my 42 gallon tank. I would suggest using a version of this system if you have a way to implement it. For one if you use a controller you will get alerts if something goes wrong if it is setup to do that. No system is infallible so things will go wrong from time to time. All systems will have their quirks but as long as you know what they are and account for them you should be good.

 

[TheBear78]

Would this work?

tank with new saltwater + an air stone

A pump on a timer that runs a few minutes a day

an overflow in sump that runs to a drain or waist water tank

pump would turn on and pump water from the new saltwater tank into the displays, old water would overflow out of the sump into a drain. . .

???

what other things to consider???

It would certainly work and it appears to use just a single pump unlike some of the other replies are suggesting?
Obviously the permanent overflow problem would need to be considered but my biggest issue, which is more of an issue with larger changes, is that of overflowing clean water.
Without draining a quantity of waste water independently you would run the risk of clean water finding its way (albeit mixed into the old water) out of the overflow. Regular small changes would probably reduce this risk to almost nothing but larger changes would certainly waste clean water.

 

[mermaid_life]

If you were to lose power and the standard water from DT got drained into the sump and out to the drain, when power came back on, which would top off the tank...Fresh salt water mix or fresh water from ato?

 

[n2585722]

If you were to lose power and the standard water from DT got drained into the sump and out to the drain, when power came back on, which would top off the tank...Fresh salt water mix or fresh water from ato?

That is a good catch. On mine even turning off the skimmer will raise the water level and I would loose water.

 

[mdb_talon]

If you were to lose power and the standard water from DT got drained into the sump and out to the drain, when power came back on, which would top off the tank...Fresh salt water mix or fresh water from ato?

This is the big issue with this type of system and why rarely used in practice.

There are ways around it like using an electronic valve for the flow out of tank that is normally off. When the wc pump turns on you also open this valve for several minutes before it closes. Other similar solutions that can work. Personally I think it adding more failure points for what can be a simple process already