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melev

Finding the right match

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4 Comments
by
melev
, 02-11-2013 at 07:17 PM (3260 Views)
I'm making a little progress on my goal to do water changes without having to lift a finger. The idea is to move water out of the tank and into the tank at the same time, and to do so in small amounts daily. From one of Randy Holmes-Farley's articles written years ago, he determined that there was just as much benefit changing 1% of the water daily as there was doing 25% once a month.

About two years ago, I bought this pump from a club member. It's a high end dual-head medical grade doser with variable speed adjustment. It can move as little as 3g per hour to as much as 7g per hour. 3g a day would be 90g a month, and 7g a day would be 210g per month changed. In the end, I'll probably change about 4g a day, or 100 per month on a 400g system.

Because so little water is changed, temperature isn't a factor at all. I have the large poly tank in the fishroom, and for the most part the temperature is within a few degrees of the reef thanks to ambient climate control. I don't use a heater nor a chiller for the saltwater circulating within.

It's already plumbed with an extra fitting to run water to a doser, but I was having trouble finding the right tubing for this pump. While placing an order with USPlastics last week, I asked if they would please look up the model pump I had and verify that their dosing pump tubing was the right kind. They told me to call the people at Masterflex, who were nice enough to look at the tubing sold on USPlastics' website. I was told the Tygon tubing should work, but was rated for 200 hours of use. Masterflex sells a different tubing rated for 10,000 hours. What? I did some quick math and discovered if the pump ran for one hour daily, their tubing would last me 27 YEARS!

They sell it in 50' lengths, but before I committed to that purchase, I was told they send out a 12" sample upon request. I asked for two 12" samples since I need to run two heads simultaneously to draw water out of the sump as new water is trickling in. They were happy to do so. Now theoretically this sample will last 27 years, so I may not ever have to buy the boxed roll of tubing.

Name: masterflex-tubing.jpg Views: 524 Size: 247.0 KB


The plan is to cut this in half and use hosebarb connections with clamps to secure 1/4" RO tubing for the distance back and forth. In a way, this should work out well because with black tubing you won't see anything except output. Once all connected, that's when I find out if the method is successful.

This has been a backburner project for a long time, but with this missing link I can finally get that "Achievement Unlocked."

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Categories
‎ Plumbing , ‎ Equipment

Comments

  1. cyano's Avatar
    so are you looking to have a constant drain or a type of solenoid that opens the same time as the doser turns on? or are you wanting to manually open a valve and turn on a pump? The way I read it was you dose in say 1% of the total water volume in a 24 hour period while the same volume flows in? If you created a sperate chamber that water levels could be read in so as to not interfere with the auto top off then you could set up switches similar to an auto top off.

    say you have a container plumbed into a drain that has a valve on it and two float switches. one float switch activates the water coming into the tank and the other activates a small pump that moves water from the tank into the container. if you could get pumps at the same rating controlled by the float switches then all you would have to do would be to drain the old water out by opening that valve.

    or you could get another separate container to drain a specific amount of water change water into with a switch hooked up to it to kill the pump when the water gets low in the holding container and then once again a container for the old water that stops the pump once it gets to a certain level.

    Either one of those would require still some level of effort on your part but it would sure beat lugging around bucket after bucket of saltwater for that massive volume.
  2. melev's Avatar
    No, that's not what I'm saying. Both heads move at the same rate because they are twin units on a single drive shaft.

    Once a day, say 3 a.m. the timer will turn on the Masterflex and run it for the duration required to move water both out and into the sump at the exact same time at two different locations until 4g has been changed.
  3. cyano's Avatar
    oh ok so that one pump will both remove and add water at the same time. that is ideal! are you going to run any type of switch to try to avoid the possible bad in this setup? or during the time that this is running turn off the auto top off just in case?
  4. melev's Avatar
    I may, but I doubt that the ATO would be affected if water enters and exits at the same pace. It should stay stable at the same height during that duration.