Neptune Dos Owners

BillNye

New member
Hi everyone,
So I've been reading up about the dos and want to know how your experiences doing water changes/dosing has been since installing the unit.

I'm planning on using it for water changes as well as dosing, going between the two by using something like this:

206000_John_Guest_3_Way_Ball_Valve_1_4_inch_QC_1.jpg


I'm looking to do a 30G water change over a weekend and then switch it back to dosing mode during the week. Maybe I can use these for multiple purposes?

Thoughts on both the Dos and the valve idea?
 
I can't speak to the valve idea, but I do have some thoughts about using the DOS for water changes.

My only concern with the DOS when using it for water changes is that Neptune has stated that the life expectancy of the the pump head is about 600 hours. Doesn't seem like it would last very long if it's in heavy daily use. Using the DOS to move 30 gallons over 2 days every week is going to rack up the hours very quickly.(in addition to whatever volume you are dosing during the rest of the week)

I ultimately decided to go with the Spectrapure LiterMeter III for the continuous water change system that I'm planning on my new build. They are on sale right now for a price that puts them in the same ball park price wise as the DOS. The LiterMeter III has been around for quite a few years and has a stellar reputation for longevity and accuracy.
 
600 hours!!? Yikes, that decided it for me. Dos sounds great because of the ease of programming with fusion, but if that's true I'd stay away OP
 
My only concern with the DOS when using it for water changes is that Neptune has stated that the life expectancy of the the pump head is about 600 hours

Straight from the DOS page: https://www.neptunesystems.com/dos/

LIFESPAN
The stepper-motor in the DŌS has a MTBF (mean time before failure) of 5000 hours. Other systems with brush-driven DC motor pumps have lifespans measured of just a few hundred hours of use. This means the pumps on the DŌS may have up to as much as 12x the lifespan of others.


I use it for AWC. I am changing 14.4 Liters a day on my 240+ gal system. The pumping is spread out over 24 hours and totals 240 min of pump time per day.

5000 * 60 = 300,000 min of pump life
At my usage, which I think is pretty heavy, mean failure time is 300,000/240 = 1250 days or about 3.5 years

I don't think that lifespan of the DOS will be a major issue.
 
My only concern with the DOS when using it for water changes is that Neptune has stated that the life expectancy of the the pump head is about 600 hours. Doesn't seem like it would last very long if it's in heavy daily use. Using the DOS to move 30 gallons over 2 days every week is going to rack up the hours very quickly.(in addition to whatever volume you are dosing during the rest of the week)

600 hours!!? Yikes, that decided it for me. Dos sounds great because of the ease of programming with fusion, but if that's true I'd stay away OP


Straight from the DOS page: https://www.neptunesystems.com/dos/

LIFESPAN
The stepper-motor in the DŌS has a MTBF (mean time before failure) of 5000 hours. Other systems with brush-driven DC motor pumps have lifespans measured of just a few hundred hours of use. This means the pumps on the DŌS may have up to as much as 12x the lifespan of others.


5000 * 60 = 300,000 min of pump life
At my usage, which I think is pretty heavy, mean failure time is 300,000/240 = 1250 days or about 3.5 years

I don't think that lifespan of the DOS will be a major issue.

Thanks for digging that up deweyhowell and doing the calculations. I Can't understand how people "hear" or read something somewhere and re-state it as definitive fact when all it takes is a few minutes to find the correct info
 
Thoughts on both the Dos and the valve idea?

I am very happy with the DOS so far. Caveat, only been running for a few short weeks :)

One thing to consider on the valve idea is your tubing length and how you will deal with the liquid in the tubing. You can always prime (flush) when you switch between dosing and awc, but if you want to set it and forget it. There will be some liquid to deal with. It might be a small amount, but I think it could make a difference depending on your dosing regimen.
 
Thanks for the responses everyone. I read that the motors were only good for some time when doing water changes/constant use so I wanted to check with all of you before going for it. I see MD and BRS dropped the price $50 so I'm thinking now's a good time, if any.

As for the valve, I don't want to set it and forget it. I was more so looking to switch it one way for water changes and then flip it for the rest of the week's dosing.

I was looking at the spectra pure life meter for water changes but I like how I can do water changes and dose with the DOS.

"Dos" anyone else have any experience using these things for WC and/or Dosing? :lolspin:
 
We're just using it for dosing and really, really like it, BUT deweyhowell brings up a good point which is that when changing out bottles of dosing solution we sometimes have to flush the lines a bit to remove any excess air bubbles. I would think that might become and issue changing between two different fluids (water change water and dosing solution). It might not be a big deal a time or two, but over a length of time I would think it would become more of an issue.
The big draw with DOS for us was the ability to use it with Apex. I think you'll be forgoing some of that in order to make it do double duty.
Still thinking about this idea...
 
I never stated that the motor had a lifespan of 600 hours. I said it was the pump heads. Per Neptune's own website, they say they need to be replaced every 700 hours on the link below. I believe it was an interview that came out around launch time where the Neptune systems rep gave the 600 hours number. I could dig around to find that source but it's not really worth the time when we are talking about a hundred hour difference. Whether it's 600 or 700 hours, I really wouldn't want to be replacing 2 $30 pump heads that frequently.

https://www.neptunesystems.com/product/replacement-pump-head/

Straight from the DOS page: https://www.neptunesystems.com/dos/

LIFESPAN
The stepper-motor in the DŌS has a MTBF (mean time before failure) of 5000 hours. Other systems with brush-driven DC motor pumps have lifespans measured of just a few hundred hours of use. This means the pumps on the DŌS may have up to as much as 12x the lifespan of others.


I use it for AWC. I am changing 14.4 Liters a day on my 240+ gal system. The pumping is spread out over 24 hours and totals 240 min of pump time per day.

5000 * 60 = 300,000 min of pump life
At my usage, which I think is pretty heavy, mean failure time is 300,000/240 = 1250 days or about 3.5 years

I don't think that lifespan of the DOS will be a major issue.
 
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You are certainly right about that. I heard it from Neptune itself that the pump heads have a life expectancy of 600 hours during an interview they gave shortly after launch. I wasn't able to locate that interview in the minute that I had available to look around this morning, but here's a link to Neptune's own site where they say the pump heads should be replaced every 700 hours.

You may wish to note that there is a difference between motor life and pump head life.

https://www.neptunesystems.com/product/replacement-pump-head/

Thanks for digging that up deweyhowell and doing the calculations. I Can't understand how people "hear" or read something somewhere and re-state it as definitive fact when all it takes is a few minutes to find the correct info
 
What you describe sounds semi-dangerous to me. What if you forget to flip the valve, and the dos (hopefully not on schedule, hopefully at least manually) starts pumping tons of elements (what ever it would otherwise be dosing). Just sounds risky IMO. I would rather just do water changes manually, or get two dosing setups.
 
Regarding the valve idea, I'd love to figure out a way to make these pumps do more than one thing, but I'm also worried about air and residual liquid in the line.

Regarding life span of the motors and pump heads, I'm not worried at all. These pumps operate at 250ml per minute. My system is 175 gallons and I am changing 1% per day.

For me, that equates to (2,475 liters * 1000 / 250 / 60) = 165 hours a year. At that rate, I'll replace my pump heads every 4 years and the unit in 30 years...

No more lifting buckets? It's some of the best money that I've spent in this hobby.
 
Dont use a valve, thats idea has room for failure.
If you plan on doing daily small water changes just get another dose, there is no easy way around it.
If you plan on using it for once a month water changes, you may as well have lines ran going to the dose for you to swap out, they're not that difficult to do. You're going to have to reverse flush the lines anyways to get the elements out of them, even with a valve. you might as well keep it safe and just swap the lines out. Thats what I do.
 
What additives do you recommend. Alk is obvious for one pump but am unclear what is best for the second pump. Can you combine Ca and Mg for the second pump? I would not want to add one without the other for fear of upsetting the balance. Thoughts?
 
The pump head life of 700 hours is relative to the tubing as it becomes more likely to split as it ages. This is true for ALL peristaltic pumps. I use Masterflex pumps for ATO and my CA reactor and routinely change the tubing every 60 months to prevent splitting and flooding.
 
Here is a chart of the expected tubing life at 600 rpm. Neptune DOS uses Pharmed tubing rating at +1000 hours. I think, maybe, Neptune rates at 700 as a precaution in their favor so if the tube splits and you are over 700 hours they have no responsibility.

http://www.usplastic.com/catalog/files/charts/PumpTubingLife.pdf

Even the tubing on the Spectrapure LiterMeter III, if it is a peristaltic pump is subjec to tube life.
 
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