Continuous water changer

[Randy1]

I'm considering using a Continuous water changing system. I remember reading about them here I belive somewhere. I would like a system that will automaticly exchange water daily. I was thinking like 1 gallon per/day. I was thinking of using one of those 2 channal dosing pumps but I don'y know too much about them. I have a tunze osmulator conected to a kalk. reactor that I would want to temporaly disable to prevent a large dose of Kalk. Anyone use a system like this would want to share thier set-up? Thanks. and don't anyone out there call me lazy..

[RobinsonFam1]

a friend of mine tried it with 2 peristalic pumps but once again he could not get the pumps equal and caused water shortage and overflows.

the only i dea i had was to use a small perstalic pump like that, figure out how much water you want to deplte a day worked out over a 24 hour period and have an ATO from the new water.

this would conflict with an evaporation rate and therefore you would have to make this work in a second chamber/container in order to regulate the change over.

you ATO for evaporation would have to completely seperate otherwise you would be adding to the salt content, or the reverse of adding too much RODI.

its a cool thought though.

[Randy1]

Right. I already use a Tunze osmulator for fresh water top-off. I'm thinking disable that with a good digital timer for say a 2 hour block. Then with another timer turn on the first pump to pump out 1 gallon into a sink drain. Then the other side of the pump turn on and replace the 1 gallon with new saltwater. Then after the exchage re-unable to ATO. unit. till the next day. thoughts??

[funman1]

You could do it with float switches and a decent controller or relay logic.
I prefer the controller method.
Use the same float switch for ATO water for the top sensor and use another float switch down lower just for this system.


Have the controller check on the water level (Make sure it's not being topped off currently.)

Then have it disengage the ATO system,
and Engage water removal pump,
then once the lower float switch triggers.
Disengage the removal pump, and Engage fresh saltwater pump.
When top float switch triggers, disengage fresh saltwater pump,
and Re-engage ATO system again, to return tank to normal operating.

The amount of water removed and replaced would totally depend on the vertical distance between the two float switches in the sump.

Greater distance, more removal and replacement.
Shorter distance, less removal and replacement.

Then just schedule the controller to do this when ever you want.
You could also add float switches to the fresh saltwater storage, so it won't even start a removal unless there is enough fresh salt water to complete the cycle.

[medic29]

I had asked the same question a while back and figured it out. Just wet tested it last night.

Check out this LINK.

[funman1]

Here's a reall quick and dirty shot of how it would be done with a LOGO system (Like I have on my tank)
I'd clean this up a bit before use and add some safteys here and there with more timers and such, but like I said it's just a basic quick and dirty Schematic of how it could be done.

[fio1022]

2 pumps(1 being a paristalic) 2 timers.Very simple...

[rutledgek]

Seems overly complex. Here are my thoughts. If you have a drain handy in the room or near the tank put a drain slightly above normal top off level. Then have a container of salt water ready mixed. Set a timer on a pump to run for the time required to change your water. With a good ATO that water will remain the same salinity and the new salt water will push the water level up above the drain and the same amount of water will be removed.

[funman1]

I thought it was pretty simple


Granted your way may work better depending on the where the drain is located.

[rutledgek]

Yeah the location of the drain is very important. I mean just slightly above the ATO line so that any waves dont push over the drain, but low enough that your ATO still works after the water change.

[funman1]

Altough this wouldn't work on my setup.
I just realized that when I shut down my return pump for feeding every night, using that method would drain all my tank water out of the sump, and be short a lot of water when the return pump came back on 20 mins later...
DOH!!!

[Mizer67]

I saw a thread once that demonstrated mathematically that less frequent larger changes actually do a better job of removing wastes. Basically when you do numerous smaller changes you are changing a percentage of the "clean" water with the dirty. Just something to think about.

[Saltcreep1]

If you are draining waste water as you are adding your new water you will be wasting some small percentage of new water.


If you dont mind spending the eaxtra money...go ahead.....

[funman1]

Originally posted by Saltcreep1
If you are draining waste water as you are adding your new water you will be wasting some small percentage of new water.
If you dont mind spending the eaxtra money...go ahead.....

Yes, but the counter argument to that is, water changes become so easy that you are more likely to actually do them on a schedule, and not skip them as often due to sheer laziness.

I know if I had a system to do water changes for me they would happen religiously once a week.

[erics3000]

i skip some water changes in my fo tank. I am building a water change station for my other tank. May be you can run some hose to your garage ..I know before I get my new tank up I want to make sure it is easy to do them ..This way they get done like you mentioned...

[BeanAnimal]

Originally posted by Mizer67
I saw a thread once that demonstrated mathematically that less frequent larger changes actually do a better job of removing wastes. Basically when you do numerous smaller changes you are changing a percentage of the "clean" water with the dirty. Just something to think about.

The opposite is really true. Once your ahead of the waste curve, the frequent water changes keep the water clean and the parameters stable.

Read the Artciles by Randy Holmes Farley, etc. on the subject.

[areze]

why not just overflow the sump to a drain line. youd need to have 2 inputs, 1 fresh, 1 salt. the salt keeps dripping in at whatever rate you choose. and the fresh would be hooked up to a controller with salinity monitoring so it can maintain the salinity with fresh water top off.

still, its not very efficient from a cost of salt and water standpoint, alot of the waste water will be "clean"... your levels will be very consistant, but not overly low.

[8BALL_99]

To me though you would waste alot of water.. I'm sure it works. But I would think you would have to change more water this way then just doing a 10% once a month.. I guess too, it would depend on how dirty your system gets to start with.. I know when I do a water change all my Parameters are spot on anyway. I guess if you had a tank that the no3 drifted up by the end of the month or maybe the CA and ALK was off by the time they did a water change then they would be better off with constant small ones to keep from having the swing in parameters..

But really water changes are pretty simple on most tanks. It takes me about an hour to change 60 gallons a month. This is only cause I use this time to suck out the grud in the sump and overflows.. If I just pumped the water out and back in, it would take maybe 30 mins once a month and thats with 3 systems. If I was on city sewer and could just pour it down the drain even easier..

However, if you do it.. I'd try to keep it simple.. Some of the idea's I've seen remind me of a Rube Goldberg comic lol. No reason to have 8 floatswitches and 100ft of wire if you can do it with just a Dual head peristalic. They run about 150 and will pump water out at the same rate it pumps it in.. That might not be the best way.. But to me the more complex it is to do a simple job the more room for error..hehe Rube Goldberg

[Horace]

You guys are making this much more difficult than it has to be.. You need a DUAL peristalic pump. Both will pump exactly the same amount both ways In/Out. I have this setup on my tank and it works flawlessly and has for several months. Randy Farley also uses this method. Its a bit more pricey than some other methods, but it works and is reliable. Well worth the investment IMHO.

[fio1022]

Originally posted by Horace
You guys are making this much more difficult than it has to be.. You need a DUAL peristalic pump. Both will pump exactly the same amount both ways In/Out. I have this setup on my tank and it works flawlessly and has for several months. Randy Farley also uses this method. Its a bit more pricey than some other methods, but it works and is reliable. Well worth the investment IMHO.

I agree.
I'm only using 1 peristalic to suck out and a mag to fill.It takes about two hours to remove what mag filled in 5 min.I use the same mag to mix up batch once a month.At the end of that time period, water level is where is should be.Peristalic pump sucks air at correct water level.
Simple...

[Horace]

I just did a search and found that my pump is actually a syrup pump for a beverage machine. Its best to find a dual version of this pump (like I have). They can be had for ~$30 w/out the power converter. They work like a charm, but are a bit noisey, which is why mine runs at 3am.

[manderx]

i have a friend who got a bare dual peristaltic off ebay for <20 bucks. he uses it for water changes, though not daily automatic ones. he mixes up a brute, then puts the peristaltic on a timer to run for 20 hours or so (a few hours short of emptying the whole brute). if he stayed on top of keeping the brute full, or worked a float switch into it so that it doesn't remove tank water when the brute is empty there's no reason it couldn't be on a timer for a couple gallons a day.

[Pbrown3701]

This is the way i have done it. However, given the chance again, i would have purchased a DUAL HEAD peristaltic pump which does in fact change exactly the same amount of water (avoids the problem of 2 seperate pumps)

[Randy1]

Originally posted by Horace
You guys are making this much more difficult than it has to be.. You need a DUAL peristalic pump. Both will pump exactly the same amount both ways In/Out. I have this setup on my tank and it works flawlessly and has for several months. Randy Farley also uses this method. Its a bit more pricey than some other methods, but it works and is reliable. Well worth the investment IMHO.

Ya, thats what i'm going to do. do you use a litermeter or an Aqua Medic pump?

[0 Agios]

Originally posted by funman1
I thought it was pretty simple


Granted your way may work better depending on the where the drain is located.

Now use a karnaf map to simplify