Continuous water change???

[Daniel@R2R Verified Admin]

I was reading a thread on...some other site...anyway... There's a guy on there talking about doing a "continuous water change" using dosing pumps that are continually changing the water instead of doing a scheduled water change (as we normally do). Does anybody do this? What would be the pros and cons?

 

[GHill762]

if you can get it set up right, it'd be nice..

I would have the export pump on a timer running for a couple minutes, then the import pump running on a float switch (only after export pump has shut off), otherwise you're going to have salinity problems..

pro's
-automated water change

con's
-potentially expensive

 

[Velodog2]

You would still have salinity problems as your evaporation will be replaced with salt water.

 

[shred5]

if you can get it set up right, it'd be nice..

I would have the export pump on a timer running for a couple minutes, then the import pump running on a float switch, otherwise you're going to have salinity problems..

pro's
-automated water change

con's
-potentially expensive

I agree the only con would be price.. Continuous water changes could possibly be the best single thing you could do for your tank.. It would eliminate ther need for additives, Stability etc.

There are some systems out there designed for continuous water changes.

Genesis Renew and Storm automatic water change and top off systems

Genesis Reef Systems | Automated Aquarium Water Handling Systems

 

[Daniel@R2R Verified Admin]

You would still have salinity problems as your evaporation will be replaced with salt water.

I'm thinking I would probably need to use a controller that could alternate between RODI and saltwater top offs depending on salinity levels. Definitely would have to work this issue out.

 

[Daniel@R2R Verified Admin]

if you can get it set up right, it'd be nice..

I would have the export pump on a timer running for a couple minutes, then the import pump running on a float switch (only after export pump has shut off), otherwise you're going to have salinity problems..

pro's
-automated water change

con's
-potentially expensive

I like the float stitch idea.

 

[GHill762]

You would still have salinity problems as your evaporation will be replaced with salt water.

not if your ato runs before the export pump.

1. ATO on float switch or other water level sensor
2. export pump on timer (or inverted float switch)
3. import pump on float switch or other water level sensor

should replace exactly what it took out, and should not have salinity issues if your ato runs first.

 

[Daniel@R2R Verified Admin]

I agree the only con would be price.. Continuous water changes could possibly be the best single thing you could do for your tank.. It would eliminate ther need for additives, Stability etc.

There are some systems out there designed for continuous water changes.

Genesis Renew and Storm automatic water change and top off systems

Genesis Reef Systems | Automated Aquarium Water Handling Systems

Excellent info!! Thanks!!

 

[Daniel@R2R Verified Admin]

not if your ato runs before the export pump.

1. ATO on float switch or other water level sensor
2. export pump on timer (or inverted float switch)
3. import pump on float switch or other water level sensor

should replace exactly what it took out, and should not have salinity issues if your ato runs first.

That does sound like it would fix the issue.

 

[shred5]

Top off would not be a problem. If you set to change lets say one gallon a day, one gallon is removed and then put back.. The system pulls out the exact same amount that is put in at the same time..Anything that is evaporated would still be handled by a top off system. This could be done with 2 dosing pumps I believe.. i know I have read how people have handled this several different ways.

I do not know how the system above works.

 

[Mike S]

Ive been doing continuous water changes using a litermeter system since last winter and it works great. There is a financial investment and space needs that go along with it, but if you keep eye out used litermeter pumps show up on RC from time to time.

It basically consists of a controll unit with a built in peristaltic pump and a second peri pump. One pump removes a small amount of water from your sump several times a day and the 2nd pump adds the exact same amount of fresh saltwater back to your system. The pumps run a few minutes apart and each event is so small it doesnt effect your ATO. The pumps need to remove and add water at exactly the same rate so it's important that they are precise.

With the litermeter system you go through a calibration process then enter in how many liters of water you want to exchange each day. It then devides that volume into about 20 pumping events each day. I think mine is set to do about 2 or 3 gallons a day and my total system volume is probably around 400 gallons. You occasionally need to recalibrate the pumps.

Let me know if you have any specific questions and I'd be happy to try to answer them for you.

 

[Velodog2]

Good luck with all those float switches fighting each other. Let me know how it works out.

Reasonably accurate metering pumps that replace the same amount as was removed are the best you can do. As nothing is perfectly accurate you will still have to monitor salinity and adjust from time to time. Not sure if the benefit is worth the effort.

 

[TruRacr314x]

I've been doing a lot of reading on this as well...as I'm wanting to do this on my 180. I'm looking at using the Litermeter to do mine combined with my Apex. As they said before, ATO interference seems to be the biggest obstacle. I personally run a Tunze and it would need to be dealt with during the cycle...here are a couple options that I've ran across...

-start the new SW pump before the removal pump. This would keep the level above the ATO's sensor. So you would start the one pump maybe 5 minutes before the other and turn them off in the reverse order. This should keep the ATO from cycling...

-use the Apex to disable the ATO during the exchange cycle...

We have a gentleman here in Cincy that uses one system to do daily changes on two tanks...and I can verify that his systems look very healthy. He also runs skimmerless. His tanks are mature and are dominantly LPS...but do have some SPS mixed in.

I think that you have to keep an eye on salinity and make adjustments as necessary. The gentleman I spoke about says that his swings take a long time. If anyone would like a link to his thread showing/explaining his process, PM me and I'll get it to you. I'm not sure if this forum allows links from other club sites...

 

[Ward9320]

I have seen this done a few different peoples tanks on different forums. The concept is that difficult. Most of the people that I have seen do this use a LiterMeter III Dosing Pump with a add on pump. One pump moves water out at the same rate the other moves water in so the only place you would need a float valve is where ever you have you saltwater reservoir so when the saltwater runs out your pumps aren't running dry.

Here is a good write up on the subject that makes it easy to understand. When I get my new 150g up and running I plan on eventually incorporating this into it.

Automatic Water Change System

 

[GHill762]

with the float switches they'd obviously need to be on seperate timers, or a controller. I would never run a float switch without a timer anyway, too much risk of it failing.

they wouldn't be fighting each other at all, and honestly you could do it with one float for the ato, and one float for the import pump. the export pump can easily be put on a timer/controller.

 

[tj51]

The one factor that everyone seems to overlook is a continuous water change is not a true water change and I'll explain. I have a 180 and I like to change 35 - 40 every couple of weeks (don't like it but need to). Of course we do this as a way to export excess nutrients. First, I use water changes to clean a lot of my tank such as siphon debris out of the sand, and chaeto and every so often I'll drain and clean my sump and use the water change water to refill it. Plus when water is being returned it is nice to use the return hose to clean off your rock work. Second, if you figure that you need to change say 28 gallons per week and change 4 gallons per day, then you are actually not changing 28 gallons of nutrient filled water. Using a 100 gallon tank, if you take out 4 gallons and add 4 gallons, the next day you have 96 gallons of "old" water and 4 gallons of new. You can't pull out just the "old" water, so you will actually be pulling out some water you just put in yesterday. And after adding another 4 gallons every day, you will be pulling out more and more "new" water. IMO defeats the purpose of the water change.

I've read about one big water change opposed to several small ones; the lessor shock on the corals and fish and a more consistent replacement of essential elements. I attempted a 5 gallon every third day method, but I like the 35 gallon every other week change.

 

[GHill762]

The one factor that everyone seems to overlook is a continuous water change is not a true water change and I'll explain. I have a 180 and I like to change 35 - 40 per week (don't like it but need to). Of course we do this as a way to export excess nutrients. First, I use water changes to clean a lot of my tank such as siphon debris out of the sand, and chaeto and every so often I'll drain and clean my sump and use the water change water to refill it. Plus when water is being returned it is nice to use the return hose to clean off your rock work. Second, if you figure that you need to change say 28 gallons per week and change 4 gallons per day, then you are actually not changing 28 gallons of nutrient filled water. Using a 100 gallon tank, if you take out 4 gallons and add 4 gallons, the next day you have 96 gallons of "old" water and 4 gallons of new. You can't pull out just the "old" water, so you will actually be pulling out some water you just put in yesterday. And after adding another 4 gallons every day, you will be pulling out more and more "new" water. IMO defeats the purpose of the water change.

I've read about one big water change opposed to several small ones; the lessor shock on the corals and fish and a more consistent replacement of nutrients. I attempted a 10 gallon every third day method, but I like the 35 gallon weekly change.

I agree with most of this, I actually prefer less WC's over more... I was merely discussing the means to do it..

 

[tj51]

I agree with most of this, I actually prefer less WC's over more... I was merely discussing the means to do it..

yea, it'd be nice to do a huge one every other month LOL

 

[Pisquini]

I have been doing this for 2 years no problem.

Hello came along this post. Thought I would tell you how I am doing It for the last 2 years...I use a switch (costed like $24) connected to my RO/DI inlet to my sump. Activated by my Neptune system. I use 2 float valves. 1 activates the inlet valve to fill for a set amount of time (30 minutes for my sump size) the second is placed a little higher then my fill line, so if for some reason the first one sticks the second turns off system that when off it is always shut. I have a 150gal tank and usally it replaces 5 gallons a day just through evaporation. I add salt as needed through a drip system I have setup with a 5 gallon pail. This has been working perfect for 2 years just using evaporation and skimmer with drain. Adding salt isn't as often as you might think...varies with temp and time of year. Hope this helps

 

[tj51]

Ok, I'm backing off of this thread. I think it has a totally title wrong. Replacing evaporated water via an ATO we all do. Water changes are to export excess nutrients. Replacing evaporated water does not export nutrients. I've seen people that have systems that don't believe in water changes and their tanks look great. However, I'm a generous feeder and as said above, I use water changes to export nutrients, clean sand, and when returning the "new" water, I like to blow it over my corals. Taking a gallon or 2 of water out of your system and using your ATO to replace it, to me and it's just my opinion is not a water change, nor is replacing evaporated water.

To me, a water change is removing a significant amount of nutrient filled water (10% is significant in my book) and replacing it with new, "clean" water. Again, a good reefer should use this time to clean the sandbed, sump, etc.