Neptune dos waterchange life expectancy?

Ecotech Marine


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Oct 2, 2015
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So I have a spare dos sitting in my fish room and I would love to turn it into a automatic water changer for my Reef. Ideally 1% would be 3 gallons a day. I am just wondering if this is too much for the dos? Has anyone change 3 gallons a day using their dos? It will be in my fish room so the noise it will make isn't a big deal. I am just wondering about real world experiences for life expectancy.
If you use a dos for water changes could you please give me some insight :)
Top Shelf Aquatics


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Oct 28, 2014
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Stamford, CT
50 gallons per tow weeks ..... I think the heads will require replacement annually, the rest less frequently than that.


A Surfing Starfish
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Aug 26, 2017
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Austin, TX
The DOS can handle it, for sure. I do about 1.3 gallons a day, set up with the AWC task in Fusion. The only limiting factor would be how often you have to change the heads out. The more it runs, the faster the heads wear out. Neptune has said this before on the Forum:

"The DŌS product web page does give a figure of 5000 hours, but that is the MTBF (estimated mean time between failures) of the stepper motors, not the pump heads; MTBF is not the same as service life or a recommended replacement interval.

The useful life of a DŌS pump head is highly dependent on how it is used. A pump head which is used for dosing of small amounts of liquids at low speed (such as 25ml/day of an additive at very low speed) is most likely going to last longer than one used in a manner which is going to have more wear and tear, i.e. for extended operations at high speed (such as larger automatic water changes)."

5000 hours doesn't seem like a lot (208 days) but that is run time only. I haven't calculated, but I imagine mine only runs less than 30 minutes a day. So if my math is right, at 30 minutes a day for 365 days a year, the motor should last 27ish years for the stepper motor (and I don't think mine runs that long, not sure).

I replaced my heads after the first year, but only because I didn't want to have issues. I had not seen a single one yet, just seemed like a year was a good time haha


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May 7, 2021
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alberta canada
I had two when they first came out. One was dosing calcium and alk the other was doing awc. I had several head failures on the awc unit, but that was back when they were new. Neptune took the old ones back and sent me new sets. They inspected the broken heads and found the flaws and improved them immensely. Thank goodness

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