IMPORTANT NOTICE: There are Amazon links on this page. However, there are not referral links and going forward I most likely will not have any here. So, I will not be making any monies from you visiting this site. I’m just doing this for the fun of it, which explains why it has been 5 months since a new post.

Living Room Aquarium
My 53G Aquarium

I’ve had an aquarium for about a couple years now. This post is going to be about my 53G tank which is relatively new to me as I upgrade my living room tank from a 20G to a 53G. “G” is meaning gallons. Primarily with this planted tank, I am currently dosing it with fertilizers to help the plants grow and to try to keep ralgae to a minimum. I also am running CO2 into the aquarium which I can go into more detail on another post. I’m focusing on my DIY auto-doser that I have created for this to help me as I’m typically always forgetting that stuff and why not just make it easier for myself?

At first, I was using a product called Easy Green from Aquarium Co-Op( and that worked great. It was relatively easy. Five pumps into my 53G once to twice a week. Once would have worked without CO2 though they recommend twice with CO2. But I decided to mix my own as I wanted to control the amount of NO3(nitrate) in my tank as it typically runs a little high. Lately it has been running 80ppm without being able to fix. So I really don’t need to be adding much NO3 into the system and in fact I need to find a way to decrease those levels to begin with which I am doing.

To start with dry fertilizers, I purchased some dry fertilizers from which got me started. Of course, this also meant that I’d be dosing something daily, which I’m sure wouldn’t go well so I decided to look at auto-dosers which I decided was a bit too much money and decided to try a DIY method.

Items needed for build:

  1. A timer of some sort. I was originally tried this timer that I found on Amazon.  Which at $3.54 as an add-on item(I used the Alexa trick) was too good to pass up. I finally settled on a smart power strip that could be controlled by Google Home or via an app. By the way, the Amazon links on this post should not have any referral links anymore, though they do direct to which you should use to help donate to your favorite charity. But further on the power strip, I just used the app to set up the timers to when it runs.
  2.  Co2 Connector – $2.50 (This might take awhile to arrive)
  3. Air Pump $6.99 – Received kit with some airline, checkvalve, and adjuster. Comes with airstones though those are not used in this setup. I’m not sure if that particular one might to be best for this build, but it does work and I will be trying a new one out that I found for $0.99 from Amazon via Slickdeals. Of course, it is no longer $0.99.
  4. Bottle – Free via recycling. You can use soda bottles, though I used my easygreen bottle which the connector fits on and works. Later I decided to go with a 1 liter bottle so I can go longer without needing to refill it.  I order a couple of bottles from and got one Amber bottle and one Cobalt Blue bottle for this purpose. Blue and Brown to help protect the fertilizer from light even though it’s in the dark in my stand anyways and to be able to determine which one has my macro fertilizers and which one has my micro fertilizers. But you can definitely choose whatever bottle you want, as long as the CO2 connector fits onto it. Bottles with a 28-410 neck works, though I beliece 28-415 would probably work better as those are the ones I believe you do see on soda bottles which the co2 adapter was designed to work with.


Original items for my Auto-doser setup

Step 1: Connect a line that reaches bottom of bottle. I used an airline, but I might switch to something stiffer. I am not sure if the flimsy tube would affect performance down the road. I might take out the plastic tube from my old easy green pump as that does fit on the nub in the CO2 connector cap.

Step 2: Connect small tube with the airline adjuster to the outer side of CO2 connector cap. Then you can place that into your bottle with water in it at the moment. Note: Make sure the outer tube is not on the same nub as the inner tube.

The CO2 connector should look like this now.

Step 3: You can put the CO2 connector cap onto your bottle now if you wish with one empty nub which will be for the line that feeds into the aquarium.

It can look something like this.

Step 4: Connect airpump with airline(with checkvalve) to the bottle at the point of the airline flow adjuster. Also, connect an airline(with a checkvalve) on the empty nub that will run towards the aquarium to feed it with fertilizer. At thise point, you can setup the flow airline into the aquarium however you want to secure it. I use a binder clip to hold mine in place. Black Clip is clipped to aquarium frame and tube is held by the silver metal prongs that release the clip.

Dosing system could look like this

The final steps would be to test it to make sure it is dosing around the proper amount. It’s best to do this with fish tank water and have it setup how you’d have it setup while testing it. Just adjust the flow to dispense however much you want to dispense in 1 minute…2 minutes, etc. I have mine set for 15 ml in 1 minute. You can have it setup for Whatever ML amount in whatever minute increment, for example 20ml over 3 minutes. It should be whole minute increments unless you have a timer that can run in seconds instead of minutes. This might not dose perfectly but should be close enough.

Of course, this is a bit experimental on my part and might not exactly work to begin with. This was an idea I got from watching a Youtube video on making a DIY Soda dispenser. There are other ways to make a DIY auto-doser which uses Peristaltic pumps like these.