Arka Vida GT Doser review

One of the other members started a similar thread a couple years ago but never actually used the doser.

I started my first reef tank (Red Sea Max C-130) in November (been running FOWLER for years) and I never really had to monitor parameters as closely before. After a few months of manually daily dosing I knew there had to be a better way (also when I travel for work, I don't trust my wife to add 4ml of A, 7ml of B, etc). I started to research various options.

For some reason, the Arka Vida caught my attention, mainly for the automatic stirring functions. Like I said, I have a 32 gallon tank so 500ml of solution lasts a long time and realistically nothing stays in suspension forever so the concentrations at the top and bottom of the cylinders has to be different.

The doser has several features that I don't see on anything else such as the stirrers, backflushing (didn't think I needed, but glad I have now), and optional slave unit integration for 4 more channels.

Now, the unit (at least mine) doesn't come with the cylinders. I figured I could make them myself out of VOSS bottles. Think again, the bottom needs to be completely flat or the stirring wand slides off to the side outside of the magnetic field!! I figured that I would just but the OE cylinders , but that proved to be more difficult than anticipated. Apparently I bought while they were backordered and I had to wait until the manufacturer made more. 2 1/2 months later I had my cylinders (had to order from Germany, more on that later). I used the VOSS bottles in the meantime without the stirring function. The OE bottles are nice. The fit properly and the stirrers work great. They are 500ml which may be small for some, but fine for me.

This item comes from Germany, and I have to tell you that the manual leaves a lot to be desired. You need to calibrate the length of the hoses first, then calibrate the dosage amount. This led to a lot of fustration because it was confusing as to what I was calibrating, I ended up watching Youtube videos in German and just watching what they were doing. I also know a bit of German so that helped. Either way, I got it set up.

Now there are many ways to set the dosing. You set how many ML to dose, then you can set the intervals (every 4 hours, every 2 days, etc). You can set a dosage scheme, dose today, then 4 days from now. One thing that I don't like is that you can only dose whole numbers and at the top of the hour. So I can't dose 2.5ml, it's 2 or 3. You can work around that by messing with the calibration amounts so it thinks its dosing 2ml.

The backflushing function was a nice to have feature I wasn't planning on using soon. It is helpful if you are dosing food (you don't want it in the air) so it cleans the line out after. This coupled with the mixer keeps the food in suspension so you get a consistent result. I am from New England, so I hate the heat. My central air turns on in May and turns off in October! This leads to high evaporation and I think that the dosing chemicals are prone to it as well. My tank is also an all in one so the unit is underneath the tank in a cabinet. There is about 4' of vertical head, but this is low volume so I don't really factor in head loss. Sometimes I would be working on the tank and when the unit would dose, nothing would come out. Of course this was troubling. I would do a manual dose and get the fluid out so I know everything was still working. I think that the chamicals in the line were evaporating and I dose such small amounts it was just taking up the lost space. I now backflush the lines and have the doser fill the lines (it knows how many ml because you calibrate it) then dose the amount. This has been working very well and it doesn't matter if the AC is on or not. The lines internal volume doesn't change. It does lead to more pump noise, but I don't really care.

The last thing that I had a problem with (and it is my problem, not the dosers) is the lack of support. They are popular in Europe, but not in the US. When I emailed Arka with a question, they were more interested in how I have one in the US than my question. I did get an answer eventually. If I have a problem, I am kind of on my own, have to fumble through the manual, or watch!!

That being said, I highly recommend it. It works very well and once it is set up dialing it in is easy.


Mixers keep the fluids properly suspended and consistent.
Backflushing lets you dose bacteria, food, etc.
High quality construction
Small footprint (the containers sit on the doser)


Lack of US support (vendors and community)
May be loud (I am not sure, this is my first and only doser. It may be normal)
Potentially small containers (500ml), not an issue for me


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Def sounds like it has some nice features.... but the lack of support would drive me nuts.

Where did you get the thing by the way.
Def sounds like it has some nice features.... but the lack of support would drive me nuts.

Where did you get the thing by the way.
I bought the main unit on Amazon ($200).

The support is lacking because no one is using it yet! It isn't that hard to figure out, but it's not like there are 100 other people who have it
The base is about 12 x 7. The top of the cannisters is about 12" from the floor, but allow another couple of inches because the hoses come straight up a d you need to allow them to bend. You also need to be able to fill the cannisters.
I'll measure them when I get home later, but I know what you are thinking. Let me save you some time, you won't find anything that will fit!

I spent an entire Saturday going to HD, Target, Walmart, dollar store, etc. Nothing has a flat bottom. The closest thing is smaller VOSS bottles but the bottom is very concave.
If the unit heads are doing the correct pressure to the lines, then you do not have any liquid return. I never heard of evaporation in the lines. But nothing is written in stone.

Nevertheless if you solved the issue with the backflushing option and you do not find changes in your Alk levels. Then it is done.

It seems like these bottles would work. I have similar 1000mL bottles and they have flat bottoms. These bottles are cheap, but unfortunately the only size that will fit on the doser is 250mL. A 1/4" muirlock bulkhead fitting on the lid could turn them into dosing containers.
If the bottom is perfectly flat then it should not be a problem. 250ml is small but it all depends on the size of the tank. My tank is 32gal. I dose about 7ml of each 2 part daily. This would last you about a month.

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