Automatic water changes - how do you do them?

[wjcastiglione]

Hey guys (& girls) - wondering how do you do your automatic water changes?

I’m setting up a 26 gallon penisula and I plan to change 10% per week.

I don’t know if it’s best to do a little bit each day? One big water change once a week?

Has anyone done experiments on this - does it even matter?

 

[Sdbuehler1]

Automated changes are great but when things go wrong it can be catastrophic. For example if the pump that’s adding new saltwater fails then you can end up with your auto water topoff replacing all the removed saltwater with freshwater.

My AWC changes out 1 gallon a day for my 100 gallon tank (1%) which is small enough that it won’t impact my salinity too much if something does go wrong. That being said I do have water levels sensors in my sump and mixing tank and alarms if the salinity gets too high or low. I also like that changing out the same amount every day makes it easier to dial in my daily dosing for alkalinity.

 

[wjcastiglione]

Automated changes are great but when things go wrong it can be catastrophic. For example if the pump that’s adding new saltwater fails then you can end up with your auto water topoff replacing all the removed saltwater with freshwater.

My AWC changes out 1 gallon a day for my 100 gallon tank (1%) which is small enough that it won’t impact my salinity too much if something does go wrong. That being said I do have water levels sensors in my sump and mixing tank and alarms if the salinity gets too high or low. I also like that changing out the same amount every day makes it easier to dial in my daily dosing for alkalinity.

Maybe I just do .25 gallon a day? I think the full 10% would be .36 gallons a day or something.

Does the one gallon happen all day long? Or do you just run it as fast as possible?

 

[Stevorino]

I have An Apex Dos that pumps in fresh saltwater with one head, and the other head pumps out the water to a drain continuously all day.

With a 26g you have a lot of lower cost options though. I’d probably just have a premixed fresh batch somewhere and replace a small jug every day or two when I feed.

 

[wjcastiglione]

I have An Apex Dos that pumps in fresh saltwater with one head, and the other head pumps out the water to a drain continuously all day.

With a 26g you have a lot of lower cost options though. I’d probably just have a premixed fresh batch somewhere and replace a small jug every day or two when I feed.

Yes - I’m going to run a dos too. No drain in my office though so I have to run a container. So you just run it constantly? Not sure that works for me since I want the ability to empty that container during working hours. Maybe I’ll just do it in the middle of the night spread out across 8 hours or something - especially if I only do 1% a night. That’s like .2 of a gallon - so If the dos screws up it doesn’t matter so much.

Since it’s in my office I want the ability to take the 5 gallon waste water and just dump it.

I have 5x5 gallon containers.

1x RODI top off
1x Saltwater
1x waste water

1x backup rodi
1x backup saltwater

I played it that way so I can constantly have extra on hand - and it all is easily contained. No mixing in office. Should just be able to swap containers when it’s time to Switch them out.

 

[Sdbuehler1]

Maybe I just do .25 gallon a day? I think the full 10% would be .36 gallons a day or something.

Does the one gallon happen all day long? Or do you just run it as fast as possible?

I’m using the apex DOS (the noisy one). I have it run as quickly as possible which is a little under 2 hours and it runs from 2 am - 4 am. I think changing out a quart a day on a 26 gallon would be more than sufficient.

 

[KStatefan]

I do 1% per day spread out every 15 minutes

 

[Garf]

Hey guys (& girls) - wondering how do you do your automatic water changes?

I’m setting up a 26 gallon penisula and I plan to change 10% per week.

I don’t know if it’s best to do a little bit each day? One big water change once a week?

Has anyone done experiments on this - does it even matter?

I automatically do my waterchanges every day, manually. Jug dripped in, jug out.

 

[Randy Holmes-Farley]

I do 1% per day spread out every 15 minutes

That’s about what I did. It’s hard to make the case that slow and steady is not best.

 

[Reefer Brent]

Got a 60 oz pitcher. One pitcher out then one fresh in every night. Fresh is mixed in a igloo/gatorade cooler with a spout.

I do a double pitcher change every Sunday.

I have a 40 gallon tank.

 

[DanP-SD]

I'm a fan of automating this task but agree with the comment above that when AWCs go wrong they can be catastrophic so you need to be careful and plan for all contingencies. I take the approach of over-engineering failsafes. I just posted a thread with the approach I built in this weekend on my newest build. You can find it here.

 

[n2585722]

I'm a fan of automating this task but agree with the comment above that when AWCs go wrong they can be catastrophic so you need to be careful and plan for all contingencies. I take the approach of over-engineering failsafes. I just posted a thread with the approach I built in this weekend on my newest build. You can find it here.

I use my Hydros and two dosing pumps on my Minnow and a dosing schedule for the water changes. It is split into 4 times a day and is currently set for a daily amount of 3000ml. The ATO has limits on the amount of time it can stay off or stay on or an alert will be sent. It it hits the maximum on time it will turn off the pump and enter and error state. The only ways out is to override the output or for the water level sensor to go to the wet state. If there is an issue this will catch it sine the ATO will stay off too long if it overfills and it will stay on too long if it under fills. Below are some screenshot of my AWC schedule, the output used to halt the ATO during the water change and the ATO output settings.

 

[javajaws]

I use my Hydros and two dosing pumps on my Minnow and a dosing schedule for the water changes. It is split into 4 times a day and is currently set for a daily amount of 3000ml. The ATO has limits on the amount of time it can stay off or stay on or an alert will be sent. It it hits the maximum on time it will turn off the pump and enter and error state. The only ways out is to override the output or for the water level sensor to go to the wet state. If there is an issue this will catch it sine the ATO will stay off too long if it overfills and it will stay on too long if it under fills. Below are some screenshot of my AWC schedule, the output used to halt the ATO during the water change and the ATO output settings.

Thx for that - helpful as I still need to set up my AWC system.


Can you explain how “42g ATO OK” works? I thought it was to turn your ATO off if either of the AWC dosers are on but you have the combiner mode set to “AND” instead of “OR”. What am I missing here?

Also, what does “AWC Halt” look like?

 

[n2585722]

Thx for that - helpful as I still need to set up my AWC system.


Can you explain how “42g ATO OK” works? I thought it was to turn your ATO off if either of the AWC dosers are on but you have the combiner mode set to “AND” instead of “OR”. What am I missing here?

Also, what does “AWC Halt” look like?

I also have the inputs inverted turned on for both inputs so they are active when off instead of active when on. So if either one is on then it will be inactive as far as the input is concerned and that will turn off the output. I also have a minimum off time of 5 minutes set on the ATO. That counter usually starts when the output turns off but the exception is when the output is being forced off by the depends on setting. In that case the 5 minute countdown does not start until the depends on clears. This will keep it from turning on during the delay between the drain pump stopping and the fill pump starting. I used a schedule on this since I was using smart dosers and those require a schedule to do this since they cannot be used in a regular output. The AWC halt is used if I want to stop the schedule from running. I will post that output below but it uses a output controlled by a switch as one of it's input and a output that turns on with the fresh salt water reservoir low sensor as the other input. So the schedule can be halted by the switch or the fresh saltwater low sensor.

 

[d2mini]

Best way for me has always been extremely small changes many times throughout the day using my ghl profilux controller. Once an hour, 24 hours/day. Depending on the amount needed to change out each time, you can either use a doser or use two separate pumps with Level sensors.

 

[javajaws]

OK, thx. It seems a bit convoluted with inverting the inputs and use of AND vs OR but I can see how it works now. I think you could done the same thing by not inverting the inputs and then using OR instead of AND. That would require you to then use it as "off if on" in the 42g ATO depends though. 1/2 dozen of one, 1/2 dozen of another so to speak...

Also - does the dose count of 4 mean that 3000 is split up into 4 partial doses throughout the day?

 

[n2585722]

OK, thx. It seems a bit convoluted with inverting the inputs and use of AND vs OR but I can see how it works now. I think you could done the same thing by not inverting the inputs and then using OR instead of AND. That would require you to then use it as "off if on" in the 42g ATO depends though. 1/2 dozen of one, 1/2 dozen of another so to speak...

Also - does the dose count of 4 mean that 3000 is split up into 4 partial doses throughout the day?

Yes it splits it into 4 doses during the day. I also do 4 alkalinity test and they come first then the water change and then the All For Reef dosing and KH buffer dosing. I figured that doing it in that order was best. I just want the output to be on when it was ok for the ATO to run and off when it was not. The other way it would be off if ok and on if not. You can do it either way.