Continuous water changes

tur4k

Member
Ok...Let's look at the risk...

- The input pump is pumping slightly faster than the output pump or the output pump fails.
* The level in my sump starts to rise. My sump can easily handle the four gallons that would be pumped into it over a 24 hour period. Hopefully a float switch would tell the controller to shut down the dosing pumps, but lets say that fails. Eventually the skimmer would start skimming like mad due to the rising water level in the sump. My Precision Marine Bullet 2 skimmer has an external collection vessel that shuts off the flow of air when it's full. This causes the skimmer to stop skimming and makes a ton of gurgling noise. At this point I notice the problem and resolve the issue, but if that fails...I either see a little bit of water on my floor from the skimmer overflowing (I can also have a water detection probe on the floor) or I notice the high water level in the sump when I get seaweed sheets out from under my tank to feed the fish like I do every morning.
* The difference in the pumps is less than or equal to the rate of evaporation. This causes salinity to gradually rise. Hopefully my conductivity probe would shut off the pumps and send me an email or a text message, but if that fails...I notice after a few days that the water level in my ATO reservoir isn't dropping. I break out my refractometer and test the water. I resolve the problem.


- The output pump is pumping slightly faster than the input pump or the input pump fails.
* My ATO makes up the difference and the salinity starts to drop. Hopefully the conductivity probe detects the drop in salinity, but lets assume that it goes undetected by the controller. I notice that my ATO reservoir that normally lasts a week is exhausted after two days. The slight drop in salinity over the span of two days causes no harm to my system and I fix the problem.


- I'm going out of town for two weeks on vacation and I'm not around to notice any of the telltale signs that something is wrong with the water exchange.

* I shut down the water exchange before I leave. I sleep easy while enjoying my vacation.



Let's look at the reward...

- Dumping water into a garbage can is easier than doing a water change.
- 4% a day is going to cause much less stress on my livestock than weekly large water changes.
- I can safely change out more water doing a continuous small water exchange than I could doing large water changes. This reduces the amount of stuff (Ca, Alk, trace elements) that I need to add to my tank.
- I don't have to worry about matching temperature or PH when doing a water change because the exchange is slow enough that it doesn't matter.
- Stability, stability, stability!!! There are no large fluctuations due to water changes in my system. Everything is happening gradually because the water exchange is slow and constant.
 

acrylic51

Active Member
The skimmer wouldn't necessarily start over skimming due to water level increase....personally I'd shut the continuous water change down till you are home to monitor and see you have the quirks worked out. No 2 pumps are going to pump exactly. Possibly only make up enough wayer to do the changes over your absence to cover the water changes? Personally not worth thejeadache of "wonder" to test it now.
 

ifirefight

Active Member
Quote:
Originally Posted by 2Quills http:///t/396486/continuous-water-changes/20#post_3533255
I say go for it. A big part of the fun of this hobby is trying stuff like this.
I agree with that statement..I loved designing my system...thats half the fun.. Im just not on board with this...

tur4k,I see you live in Florida..I do also..according to your profile you have a 90 gallon..thats a fairly large tank and can handle small flucuations in temp,alk,cal,ph etc...without any issues.. I have a 130 with a 45 gallon sump..just did a 45 gallon water change today like I try and do every 3 weeks or so...I also use NSW,so I dont stress so much about balancing ph,salinity,etc....i test it every time but almost every time its right on the money..even with that large amount I change..and sometimes I do 60 gallons....I have never had any stress related issues..
I like the theory behind your idea......but because I use NSW,I like to do a change as soon as I collect the fresh new water,and not let it sit in a container for days or weeks.
 

tur4k

Member
Quote:
Originally Posted by acrylic51 http:///t/396486/continuous-water-changes/20#post_3533258
The skimmer wouldn't necessarily start over skimming due to water level increase....personally I'd shut the continuous water change down till you are home to monitor and see you have the quirks worked out. No 2 pumps are going to pump exactly. Possibly only make up enough wayer to do the changes over your absence to cover the water changes? Personally not worth thejeadache of "wonder" to test it now.
I would definitely shutoff the exchange if I was going to be gone for more than 24 hours. At least until I had this up and running for several months. Even then I probably wouldn't let this run unattended for more than a week.
 

tur4k

Member
Quote:
Originally Posted by 2Quills http:///t/396486/continuous-water-changes/20#post_3533255
I say go for it. A big part of the fun of this hobby is trying stuff like this.

I just ordered the LiterMeter III and a water exchange module. After all of the arguments in this thread I decided to proceed with this plan before adding the controller. My pros vs. cons post made me realize that I can determine if anything is out of balance by keeping an eye on my ATO reservoir and by using the float switch that comes with the water exchange module.

I'm totally in agreement with you. Setting up stuff like this is what makes reef keeping fun. I can always use extra dosing pumps if for some reason it doesn't work out.
 

tur4k

Member
I just finished setting this up. I currently have it programmed to exchange 4 gallons (15.14L) every day. It accomplishes this by exchanging 100.93 ml (a little less than 1/2 cup) 150 times at day. About every 9.6 minutes pump A turns on and pumps 100.93 ml of fresh sea water into my refugium. Pump B turns on when pump A finishes it's run and pumps 100.93 ml from my refugium into a drain.

So far it seems like a pretty slick setup. I'm going to keep a very close eye in it to make sure there are no problems.
 

beaslbob

Well-Known Member
Quote:
Originally Posted by tur4k http:///t/396486/continuous-water-changes/20#post_3534209
I just finished setting this up. I currently have it programmed to exchange 4 gallons (15.14L) every day. It accomplishes this by exchanging 100.93 ml (a little less than 1/2 cup) 150 times at day. About every 9.6 minutes pump A turns on and pumps 100.93 ml of fresh sea water into my refugium. Pump B turns on when pump A finishes it's run and pumps 100.93 ml from my refugium into a drain.

So far it seems like a pretty slick setup. I'm going to keep a very close eye in it to make sure there are no problems.
best of luck and best tank ever.

I'm concerned however about using two pumps. My fear is they will never be exactly matched. better to have a pump add water and the extra water drain down an overflow. .

but then what do I know? (don't do water changes LOL)

my .02
 

ifirefight

Active Member
Quote:
Originally Posted by beaslbob better to have a pump add water and the extra water drain down an overflow. .

Now THATS not a bad idea.......................Less that could go wrong......just trying to think it through...Not sure excatly how to make that work with a system that has overflows already....Perfect idea for a "closed system"....
 

beaslbob

Well-Known Member
Quote:Originally Posted by ifirefight http:///t/396486/continuous-water-changes/20#post_3534457
Now THATS not a bad idea.......................Less that could go wrong......just trying to think it through...Not sure excatly how to make that work with a system that has overflows already....Perfect idea for a "closed system"....

the overflow would maintain the sump level not the display level.
you might also have to "drip" freshwater to replace evaporative loses. (otherwise salinity would rise)
then to start a "water change" pump to pump new saltwater to the display.
So the overflow way down at the sump with the old water starts overflowing. Which will then stop overflowing when saltwater is not longer being pumped to the display.
my .02
 

ifirefight

Active Member
Quote:
Originally Posted by beaslbob http:///t/396486/continuous-water-changes/20#post_3534484
Quote:
Originally Posted by ifirefight
http:///t/396486/continuous-water-changes/20#post_3534457
Now THATS not a bad idea.......................Less that could go wrong......just trying to think it through...Not sure excatly how to make that work with a system that has overflows already....Perfect idea for a "closed system"....

the overflow would maintain the sump level not the display level.
you might also have to "drip" freshwater to replace evaporative loses. (otherwise salinity would rise)
then to start a "water change" pump to pump new saltwater to the display.
So the overflow way down at the sump with the old water starts overflowing. Which will then stop overflowing when saltwater is not longer being pumped to the display.
my .02
If you had an "overflow" in the sump area...being that the sump stays a constant height....except for the return area...then this would work...So if i had drilled a hole in my return area of the sump/fuge,a hair higher than my normal water level...As I pump in NEW water ...the old water will over flow out of the hole.... this might just work...
 

beaslbob

Well-Known Member
Quote:Originally Posted by ifirefight http:///t/396486/continuous-water-changes/20#post_3534521
If you had an "overflow" in the sump area...being that the sump stays a constant height....except for the return area...then this would work...So if i had drilled a hole in my return area of the sump/fuge,a hair higher than my normal water level...As I pump in NEW water ...the old water will over flow out of the hole.... this might just work...

I think you got the idea.
 

ifirefight

Active Member
This would work fine...just not for my system...I dont have an area to drain the water to...but I like the theory better than the one pump putting water in and another pump taking water out idea.......This would be the way to go IMHO...EVEN if the pump got stuck in the ON position...and pumped 50 gallons of water in...It wouldnt be an issue,because 50 would go out...I might have to look into seeing if I can transfer my system into this....
 
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