DOS Dosing and Fluid Metering System - Neptune Systems

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DOS Dosing and Fluid Metering System - Neptune Systems

89% Recommend this to a friend (25 of 28)

SKU: 208869
In Stock: 158
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Quick Overview

DOS – Dosing and Fluid Metering System

The Neptune DOS Fluid Metering System is one of the smartest dosing pumps on the market. It will hook directly to your existing Neptune Apex or Apex Jr. giving you the ability to program both pumps independently for what ever kind of dosing your tank may need. The DOS pump includes two pump heads for the most common of two part dosing, but it is not limited to just two part dosing. You can use it for automatic water changes once a week or even once a day, minor trace element additive dosing, liquid food dosing, or pretty much any other liquid your tank may need dosed in metered amounts.

You simply just hook the DOS Fluid Metering system to your Apex controller with the included AquaHub cable and with the Fusion cloud software programming a dosing pump has never been so simple. The DOS system when interfaced through fusion can be programmed to dose a certain amount of liquid between certain intervals of the day. The DOS pump is so smart it will even change the speed of the motor depending on the amount needed to be delivered to the tank to keep noise at a minimum.

  • 2 part dosing

  • Liquid food dosing

  • Additive delivery

  • Micro-quantity dosing

  • Auto water changes

 Simply hook this system up to any Apex via an Aquabus cable to begin DOS-ing today!


Full Details

Neptune DOS Instructions


The #1 reason people purchase a dosing system for their aquariums is for consistent and easy dosing of 2-part solutions (calcium and alkalinity) to their reef tanks. The most common method for doing this today is to use standalone dosing pumps and run them on a timer using seconds or minutes to determine how much to dose. This is not only confusing, but also prone to inaccuracy.  Everyone knows that when measuring a fluid it is done by volume, not time. Every dosing calculators out there uses volume. So, with the DOS (and the Apex Fusion interface) you simply enter the amount you want of each part of the additives (one on each pump) and what hours of the day you want it delivered. The DOS then sets up all the dosing intervals within that time period. When that time interval is finished, the exact volume you set has been delivered.  It even automatically chooses the slowest speed necessary for the pump so that it minimizes noise.


  • Automated water changes - Water changes with the DOS are super easy.  All you do is place your empty vessel and your fresh stock of saltwater under your stand. Then, with the Apex Fusion wizard just tell it an amount of water you want to change over what length of time and the hours of the day you want it to happen and it figures it all out for you.  It will perform an automatic, continuous water change for you. It gets better. If you have our dual optical water sensing accessory Apex Fusion will send you an email or text message letting you know it is time to change out the jugs.  Less time pumping, siphoning, and sloshing water and more time enjoying a great aquarium.
  • Dosing micro amounts - If you need to dose tiny amounts of a particular solution, element or other fluid (like vodka dosing or Zeovit systems), the DOS is the perfect solution due to its precision controlled stepper motor. This ability to control pump movement in such a refined manner means that you can dose all the way down to 0.1ml at a time!
  • Large diameter tubing - Larger size tubing means that your pump does not have to work nearly as hard – or stay on for longer cycles. The most popular dosing pumps on the market use tube fittings with the tiny diameter of 1.67mm. The DOS uses much larger tubing and fittings. In fact, at 3.33mm in diameter, the pump on the DOS can handle 4x the flow of the most common pump style on the market.  This means that your pump (and motor) will run 1/4 the time to pump the same amount of fluid.  Less run time means long pump life.
  • Headache free interface - Programmability using Apex Fusion makes dosing a breeze. 
  • Quick and easy tubing changes - No matter the pump, your tubeset will eventually go bad.  Changing out the peristaltic pump tubing on the DOS is a snap. Literally! All you need to do to change out the pump tubing is squeeze the pump head and remove. Then take out the tubing, replace with a new one, and snap it back on. No screws, no impossible snap on covers and no fussy loose rollers to mess with. And, because you are not changing out an entire pump head, your costs are lower as well!
  • AdaptabilityThe DOS has an accessory port that will enable it to be connected to the DDR – Dual DOS Reservoir.
  • Super silent operation The Neptune Systems engineering team has taken extensive steps both in how the pump operates as well as the enclosure design to ensure that the DOS system is one of the quietest dosing systems on the market for the fluid volumes it delivers


  • DOS pump
  • Aquabus cable
  • Power supply
  • 4 meters DOS tubing



  • Size (Approx.): 9.5″ x 5″ x 5″
  • Weight (Approx.):  4 pounds
  • Lift Height: 24 feet (minimum at MSL)
  • Suction Height: 24 feet
  • Flow Rate: Variable (0.1mL – 250mL/min)
  • Power Requirement:  110/120V or 220/24oV
  • Requires:  Apex, Apex Lite, or Apex Jr.



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  • Bad product By ibondy on 9/4/2017

    I am a big fan of Neptune products, but this pump is one of the worst pumps I ever used. Had to send for repair 2 times over the last 12 months after one or other pump stopped working. Was told that pump should not be used in a 'moist environment' ?!?! Had to pay for repair as they refused to honor warranty due to 'moisture damage'. Now one of the pumps is not working again.
  • DOS FOR AWC By FLSharkvictim on 8/12/2017

    I only use the DOS for automated water changes only and it works amazing. Well worth every single penny. It's a lit bit noisy but nothing to loud I have read on some forms. If you're sick of doing water changes the DOS is for you..No more carry jugs, not more buying saltwater from your LFS. Also, very easy to set up your schedule for how much ever water you want to take out and add..HIGHLY recommended.
  • So far, after 9 weeks, it's working great for me By Randall on 8/8/2017

    I can't speak to long term longevity, and some of the other reviews leave definite cause for concern about how well this gear will hold up. Also, I've had problems with other Neptune gear failing prematurely. However, so far this pump is doing a great job of dosing for me. In fact I have two of them. They are super easy to program for frequent tiny dosages, through the Apex interface, and they seem to be pumping accurate amounts. (It's also easy to recalibrate each pump if you have any doubt, and easy to flush lines of any air bubbles.) I was having a miserable time dosing two-part manually with pH swings and inability to maintain adequate alk levels; the doser fixed all that.
  • Garbage. Skip it By Jennifer on 6/1/2017

    Horrible pump. First pump was broken, new out of the box. Apex wanted a hefty sum to fix it and blamed me for the issues.

    Second pump broke 6 months later. Wheels stopped turning. Purchased new wheels as it says they need to be replaced every 6 months or so many turns/hours. Still would not work with new wheels.

    I wasn't willing to send the broken doser to Apex again, as they proved to me, the customer is always at fault, even with junk for equipement.

    I went to a BMT01 doser and haven't had any issues with it.

    Skip the Apex Dos.
  • Awesome, simply awesome By Casey on 1/3/2017

    This dosing pump is amazing. Super simple setup and you can dose literally a drop of whatever you are dosing. It's pricey but honestly, if you've already spent the money for the APEX, you owe it to yourself to get this. 10/10 would buy again.
  • Works great so far. Its only been a few weeks By steven on 5/23/2016

    I purchased for automatic water changes on my 300g. Right now im changing 6 gallons per day. so far it has worked flawlessly. It was very easy to setup using fusion. 1 thing to watch out for. If you select remove water during setup the pump will spin backwards.

    For dosing this pump is fairly quiet, but when you are doing large water changes like i am the pump runs in high speed and it is noisy.
  • Noisy By David on 4/27/2016

    Only 5 weeks old and it started making a clicking and humming noise loud enough to annoy anyone watching TV in the same room, and the pump is inside the cabinet! I emailed support, sent pictures as requested, swapped the left and right heads for them. The answer they came back with was this: "It's highly likely more plastic pump heads will result in the same sounds. The plastic flexes and makes these sounds." That's a quote! I told them it didn't start out this loud. I know everyone says the service is great. My service experience was disappointing.
  • Awesome By ALEX on 4/11/2016

    This doser does exactly what it should. Precise and accurate dosing is very important to the reef tank. This doser takes the guess work out and with a few simple steps it's ready to go.
  • Well designed and easy set-up By Kane on 3/31/2016

    DOS was easy to install and set-up. Calibration is a few simple steps. Using it for 2-part addition. Only problem I had was not enough tubing so had to order more to install.
  • Great for 2 part and water changes! By craig on 3/23/2016

    Makes life very simple for 2 part and water changes (using 2 on the system)... the latter being my favorite benefit.
  • Great Doser By Mark on 3/6/2016

    I love this Doser. I use it to dose 2 part. It was was easy to set up and is very quiet. Highly recommend. I set it up in Apex to dose Alk at night and Calcium during the day. Works like a charm and keeps my PH up at night. I also got the DDR to go with the DOS and now i know exactly how much 2 part i have left and Apex will notify me when the Alk or Calcium mixes get low.
  • If you have an Apex and are looking for a doser...this is it. By BTibb on 3/6/2016

    With all the options, abilities, BRS customer support, and Neptune brainer even with cost. Picked up one for 2-Part dosing, will be adding secoknd for AWC.


Ask a question

Product Questions

In the video, it states that the rollers are only good for 600-700 hours. How much are the replacements and where can I buy them?
Question by: Chris on Mar 29, 2016 2:55:00 PM
Great question!
We are not aware of the rollers available for sale from retailers at this point. For replacement rollers you will want to contact Neptune Systems directly. Feel free to let us know if you have any further questions!
Neptune Systems (Apex Controller) – 408-779-4090
Answer by: Connor (Admin) on Mar 30, 2016 12:03:00 PM
If I set this up for auto water changes and my tank is on the main level of my house and the salt water barrel is one level down (basement) and over about 20 ft can this pump handle that pull?
Question by: Drew Halvorson on Jan 27, 2016 8:16:00 PM
Great question!
The DOS has around a 20" head height, this means that you would need to place the pump either a little higher or lower in the line from the storage to the tank. It can work well however. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Feb 4, 2016 3:24:00 PM
So does this dosing pump have the tubing or not as the gentlemen up top asked before and your answer defers from what your page states.

DOS pump
Aquabus cable
Power supply
4 meters DOS tubing
Question by: Matt on Jun 9, 2017 3:15:00 PM
Sorry for any confusion. That question/answer was originally provided when the product was first introduced to the market and was based upon different information. The DOS pump does include tubing with the unit.

Have a great day!
Answer by: Zack (Admin) on Jun 13, 2017 11:56:00 PM
Will this work using the apex controller gold system?
Question by: Omar Elliott on Jan 16, 2016 12:56:00 PM
Great question!
This works great with the Apex controller gold! Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Jan 26, 2016 5:31:00 PM
Can I put this doser in a refrigerator? It would be to feed liquid food to my aquarium.
Question by: Justin on Jun 6, 2016 2:39:00 PM
Certainly can work in cooler environments. We recommend ensuring you are following a good build thread if dosing refrigerated food. Ensure to use volute to draw food into a cycling pump to ensure no left over food remains in the warm doser tubing.
Answer by: Connor (Admin) on Jun 8, 2016 6:26:00 PM