Continuous Water Change?

[The_Godfreys]

Read some older articles about this and was considering for my 125g.
Is anybody using it?
Pro's / Cons?
How to?

Was thinking about a dual head dosing pump. One head removing water from sump, the other replenishing. If they are well matched should cancel out. Would maintain ATO for evaporation.
I understand that this reduces the effectivness per gallon slightly but should greatly add to the stability of the tank.
Anything else I need to think about?

Thanks, Jim G.

 

[Ronnie]

One word Dialyseas look into it. Dosing pump would work but i would use a controller with float switches in case something went wrong. just my 2 cents.

 

[The_Godfreys]

The Dialyseas looks real interesting but well outside my budget.
I'm thinking much more simple (and cheaper)though I do have a few inputs left on my APEX that could monitor sump level to avoid catastrophy. Good idea.
I figure a dosing pump would put the water in slow enough I probably wouldn't need to pre heat it.

 

[JohnK]

Here's exactly what you need;
http://www.bostonreefers.org/forums/showthread.php?105485-FS-2-Part-Dosing-Pump

Control that with a digital timer and it will be super consistent and reliable.

 

[stevenp]

Only downside of those paristaltic dosing pumps is that you're going to burn through a lot of tubing pumping the kind of volume required for your application.

I have a dual head peristaltic pump I purchased for automatic water changes but decided not to use it because changing tubing every 3 months was going to be too much of a hassle for me.

 

[JohnK]

What kind of pump do you have Steven? I have a couple of those cole-parmer pumps that have been running for years without wearing the tubing out. One in particular has been in nearly continious use 23/7 for 5 yrs and the tubing is still doing just fine.

Now aquamedic dosers are a whole different story

 

[dcforester1]

I was doing this with a three head pump which was tied into my ATO. I evaporate 2gals/day so that's what I was changing. The problem I ran into was my water was in the basement and it wouldn't even out overtime. I think it was from the amount of force to pull the water upstairs. I tried a check valve and still had some trouble. Doing it with it without the ATO should work fine. Randy H does it and has a article on it. When I do my tank over I am going to use it. One less thing to worry about. Good luck and keep us posted

 

[stevenp]

What kind of pump do you have Steven? I have a couple of those cole-parmer pumps that have been running for years without wearing the tubing out. One in particular has been in nearly continious use 23/7 for 5 yrs and the tubing is still doing just fine.

Now aquamedic dosers are a whole different story

Wow. I have an old Cole Parmer as well, with brand new heads. I bought it from Greg who told me I would eat through tubing every few months, but I never actually tried it. It's just been sitting idle in my fishroom for nearly a year. Maybe I'll give it a shot.

 

[JohnK]

It may depend on the size of the tubing and or the RPM of the pump, but I have yet to wear out any.

That said, I must admit that I didn't do the math before posting. At about 2 gal per day, this would be a continious operation at 6 rpm, so if anything would wear on the tubing that would be it

 

[Shallowwaters]

I think ReefFiller pumps would work for this concept because they can be run continuously and have a larger volume range than dosing pumps. Also, this Genesis Renew system looks like a very interesting option for consistent, small water changes. http://www.genesisreefsystems.com/products.php?cat=9 Would like to know if there are any good threads on continuous water changes.

Here's Randy's article - http://www.reefkeeping.com/issues/2005-10/rhf/index.php

 

[shawn]

I've had great results with "pharmed" tubing - great life. Just use it for the part that goes through the pump and use double-barb fittings to cheaper tubing outside the pump. I got it from: http://www.mcmaster.com/#pharmed-tubing

 

[ffsteve]

if you have a 180g tank with a 30g sump how many gallons do you need to change a day to make it work out?

 

[shawn]

If you mean give the same or better results as your current change schedule, how much do you currently change at once, and how often?

As as a somewhat simple rule of thumb, if you are currently doing changes of a size of around 25% (at whatever frequency), I'd suggest increasing the total change by 2% over the same time to cover the inefficiency of the continuos change. For example, if you were changing 25% every two weeks (let's call it 52.5 gallons), set up the continuous water change for 27% every two weeks (56.7 gallons), or 4 gallons a day. If you were changing around 10% every two weeks (21 gallons), set up the continuos water change for 11% (23.1 gallons), or ~1.7 gallons a day. If you do something like 50% water changes, you'll need to increase up to 53% with continuous water changes.

Here is a really old thread on the subject:

http://www.bostonreefers.org/forums/showthread.php?3554-Continuous-(automatic)-water-changes