DOS for automatic water change

Got my DOS yesterday from Home Aquatic Supply. Thanks again Ryan for meeting me for delivery.


First impression: Nice looking unit. Rather large, which isn't a problem for my fish room, but may be if you have space issues under a stand. Seems heavy duty and solid. They include a graduated cylinder for calibration. Instructions are all online, and easy enough to find. The "prime" buttons on the unit are nice. I did have to buy more tubing as they only include 4 meters or something. Standard 1/4" OD vinyl tubing from lowes fits perfectly.


The setup: I'm using this for a continuous auto water change. Pump 1 is removing the old salt water from the skimmer section and running it down the drain. Pump 2 is taking fresh salt water from my barrel and adding it to the return section. Not one to thoroughly follow directions I assume these are like every other dosing pump and hook up the inputs/and outputs accordingly. Pump 1 in from the tank, out to the drain. Pump 2 in from the barrel and out to the tank.


Calibration: Piece of cake. I ran the calibration process with all my tubing in place. I think this would be the most accurate way even if the instructions don't indicate this.


Prorgamming: I used fusion to program and it was simple. I followed the directions and programmed pump 1 to "remove" my volume of water over 24 hours, and pump 2 to "add" that same volume over 24 hours. Now here is where the input/output connections come into play. By setting up pump 1 in a "remove" state it actually runs it backwards. Which in my case meant it wasn't pulling water from the tank. No big deal, I just switched the lines around and all was well...or maybe not. I manually turned the pump to on to reprime and check it out. Pump runs forward- not what I want. If I want to manually turn it on, I want it to be removing water...There doesn't seem to be anyway to manually run the pump backwards. So I go back and change my programming so both pumps are programmed to "add" and run the lines how I initilly had them. I still need to add some float switches and failsafes, but its working fine for now.


So its all programmed and running.


Thoughts:


I haven't played around a whole lot with it, and did just the very basic of programming. It should work good for what I wanted. The ability to tie it into the apex and have all those programming options is what really steered me to the DOS vs. the litermeter that I was considering.


This thing can be loud. With the volume of water I have selected it runs the pump at the high speed. There are several speeds depending on the dose level. The higher speeds give off a high pitch whine that is suprisingly loud. There are suggestions on how to limit sound transfer, but I don't see it making much difference. At the low speeds its hardly audible. With the "basic" programming there are no options to change pump speed or time. You set the timeframe and volume and it does all the work. In my case it runs the pump for about a minute ever 10 minutes. Kind of annoying with the pump noise. I'd rather run it at a slower (quieter) speed for a longer interval every 10 minutes. and still divide it over 24 hours. It probably can be done, but much more involved. I'll see if I can hear it in the bedroom. If I can't I'll just run it at night. If I can I'll run it while I am at work.


I've still got some playing around. But those are my initial thoughts after playing around with this thing and getting it set up this morning.

 

$350 but with the 10% off to GIRS members, and sales tax final was $340.
Cheaper than the Litermeter 3 alternative I was looking at, and with my apex system its much more flexible of a system.

 

Right now I have it set to change like 40 gallons a week. Not quite 6 gallons a day. I don't intend to do that long term though. Once I get things cleaned up and stabilized I'd like to be able to drop it back to like 15 gallons a week or so. Currently I have a 55 gallon drum for a saltwater, but I am looking for something like a 100 gallon vertical tank.

 

The only complaint I have about this thing is the noise it makes running at the high flow rates. It really is rather annoying.

I have changed like 30 gallons of water this week without doing a thing. That part I love.