How to get Neptune DOS more accurate?

bubbaque · Feb 28, 2017

I am wanting to get the DOS to be more accurate. I know they have a calibration for 40ml but I am wanting to do AWC, with 1000's of ml a day. Even when I tested it at 100 ml's it was off a little.

Any advice?

thewbell · Mar 1, 2017

How are you programming the AWC? The way mine is set up it changes 1 gallon (3786 ml) between 12am-8am and 8pm-11:59pm. I used the wizard to set it up and it runs about every half hour and changes 39.4ml at a time.

bubbaque · Mar 1, 2017

I used a graduated cylinder to calibrate it but if it happens to be slightly off at 40ml, which is what they calibrate to, even if it looks spot on, at 9000 ml a day could end up being quit a big difference.

I calibrated both heads to 40 ml and then had them dose two cups each just see how accurate it was and one dosed slightly more than the other. That's gonna be an issue over time. One of the dosing heads is gonna end up pulling out more water than one is putting in or vise versa.

DBR_Reef · Mar 1, 2017

A quality 50 ml graduated cylinder is about as good as you are going to get. The people that I know that do awc this way tend to have to adjust their salinity every once and a while, or dial in the salinity of the fsw so that the ato corrects the difference. However, the best way to do awc is not with a dos, but with a dual head peristaltic pump. The stenner ones are continuous duty rated. A bit pricey, but you will probably never have to buy a pump again, they are nearly perfect 1:1 in and out, and any drift happens to both pump heads.

p7willm · Mar 1, 2017

If the DOS is off by a little the salinity may drift. You also take out salt water when you empty the skimmer. I use the DOS to change water and when I mix new water I also test the tank and adjust the new water to bring the tank back to what I want. I just started mixing the new water a little low and every day I check conductivity and if It is low I add a little more salt water.