Pressurized CO2, Equipment, Flow and Fertilization
First of all before I begin I would just like to say I am writing this article to help beginners understand fertilizers, CO2 and how to set up a pressurized system for planted aquariums. This is mainly so I have something to refer back to as I find I get asked a lot about setting up a pressurized system.
Now there are many ways of going about injecting CO2, but in this article I will refer to the method that I find most cost effective and efficient.
This will be a home made Fire Extinguisher Kit along with home made Macro and Micro Fertilizers which will save you £$£$£$£ and will last for months if not a year!!!!.
I will also cover Equipment that will be needed and I will also cover flow and how to calculate how much flow you need for a CO2 fertilized tank!
If any links in this article become outdated or don’t work then please PM me and let me know and I will emend a.s.a.p.
(Apologies to anybody in the US as all links are UK based.)
Now a Fire Extinguisher is perfectly safe to use and no more dangerous than using a pressurized CO2 canister from an actual kit
the only difference is the cost!
However having said that due to the rules on this forum and to cover my own back I have to put the following…..
This can be dangerous as pressurized gas is involved.
This can be dangerous as pressurized gas is involved.
Myself and Tropical Fish Forum accept NO responsibilities for any injuries caused whilst following this article and instructions.
Do this at your OWN risk.
Ok, first things first and that’s the Equipment needed. Yes the first initial cost can slightly exceed £100 but once you have the equipment it’s very cheap to run and maintain, especially compared to dosing liquid carbons in the long run. Below I have put together a shopping list along with prices and links to help you find the equipment that you need. Now these items are what I believe to be the best value for money, however the internet is a big place so with a little more time and research you may find some of the items a little cheaper.
- 2KG CO2 Fire Extinguisher £28.00
2. CO2 Regulator with Solenoid and Needle Valve £54.00
(If these are sold out or not available, message the seller he is very helpful, he sells a lot of these and will get them back in stock shortly)
3. Bubble counter £5.20
(Please bare in mind there are many different types of bubble counters, this is one of many. Might be worth researching which one will suit you. However this one is perfectly fine and will work on any set up)
4. Drop checker with Reagent/ Bromothymol Blue £10.00
5. Non Return Valves £3.00
6. CO2 Tubing £6.00
(airline tubing MUST NOT be used as an alternative)
7. 4DKH Solution £4.00
8. Mains timer £6.00
And finally you will need a diffuser of some kind, there many to choose from.
Inlines, Ceramics, Atomizers and Reactors to name a few
Now if you have an external filter I highly recommend an inline atomizer diffuser as these almost achieve 100% diffusion.
See Links below. Please note the different sizes for different filter hose size.
Make sure you get the correct one that will fit your filter hose!!
16mm – 22mm Inline Atomizer £15.00
12mm – 16mm Inline Atomizer £15.00
8mm – 12mm Inline Atomizer £15.00
Their are also CO2 Reactors. Very popular in the States and very good at diffusion. Usually used for larger tanks. These also work with an external filter and usually require 1000LPH minimum in order to work. They can also take up a lot of cupboard space.
CO2 Reactor £64.95
If you don’t have a external filter you will need a diffuser which will be place inside your aquarium. If this is the case I highly recommend an Atomizer.
Again these are fantastic for diffusion and are far more superior to glass ceramic diffusers.
Which form of Diffuser to have is really upto you and your set up
Shopping list grand total of £131.50 approx depending on which diffuser you get.
Not bad considering what you’re getting.
That’s everything you need accept your fertilizers which I will cover now.
Ok like I said before, I’m going to talk you through on how to make your own Micro and Macro fertilizers as this is thee most cost effective way to dose your ferts.
Now you could go and purchase TPN+ or Neutro+ which are excellent products
but why pay 10X more just to have someone mix up your ferts for you.
My method will cost under £20 and will last months if not over a year on a tank as large as 200 Liters!!!
Below I will show you what you need to buy and talk you through on how to make a similar formula as these big named brands
OR how to dose EI which is my preferred method.
What are Micro and Macros?
Micro and Macros are two different kind of fertilizers plants need to survive.
Micros (Also referred to as Trace) consist of Iron Copper Manganese Zinc Molybdenum and Boron
In my opinion, all tanks Low Tech and High should be dosed daily with a Micro fertilizer.
Macros (Also referred to as KPN) consist of Nitrates Phosphates Potassium and Magnesium.
Normally in a Low Tech tank, fish waste will provide enough of these Macro elements that we don’t have to add them.
However in a High Tech tanks, whether your injecting CO2 or using liquid carbon, Macro ferts are a MUST as your plants will be absorbing these elements at an accelerated rate. If any of these nutrients become exhausted your plants will suffer and will get deficiencies. If this happens you will be opening a door for algae to creep in which is what we don’t want.
If macro and micros are dosed daily though and CO2 is kept stable, this should not happen.
Ok, so where do you get these ingredients to make your own fertilizers?
Get the EI Starter kit and it will provide everything you need for £19.99
I promise you this stuff will last months upon months on end and its excellent quality!!!
This kit will provide..
2 Dosing bottles which will help you mix and measure out dosing amounts.
1 Bag of Cheleted Trace Elements (Micros)
1 bag of Magnesium Sulphate (Macro)
1 bag of Potassium Nitrate (Macro) and
1 bag of Potassium Phosphate (Macro)
When you run out or run low simply just buy what you need rather than buying the starter kit all over again.
Mixing & Dosing My Macros & Micros
Ok, first of all I’m going to start with EI dosing.
EI dosing in laymen terms basically means overdosing with fertilizers through out the week to make sure you never run out of any key nutrients at any given time.
Don’t worry this is perfectly safe and has been practiced for a years by the very best and experience aquascapist in the world!
At the end of the week you do a big water change (50%) to reset everything, and then you basically start again.
EI also normally means (Not always) you dose Micros and Macros separately on alternate days.
Here is how to mix and dose.
Mixing Your Macro Solution
4tsp Potassium Nitrate
1tsp Potassium Phosphate
6tsp Magnesium Sulphate
500ml of boiled and cooled Water
Leave to dissolve overnight
Mixing Your Micro Solution
2tsp Chelated Trace Elements
500ml of boiled and cooled water
Leave to dissolve overnight
Here is a video demonstrating how to mix
Dosing schedule For EI
Monday – Dose Micros (10ml per 50ltr of Aquarium water)
Tuesday – Dose Macros (10ml per 50ltr of Aquarium water)
Wednesday – Dose Micros (10ml per 50ltr of Aquarium water)
Thursday – Dose Macro (10ml per 50ltr of Aquarium water)
Friday – Dose Micros (10ml per 50ltr of Aquarium water)
Saturday – Day Off
Sunday – 50% Water Change & Dose Macros (10ml per 50ltr of Aquarium water)
If you would like to mix an all in one solution like Neutro+ or TPN+ rather than dose EI then simply Mix as follows..
48g Potassium Nitrate
2.2g Potassium Phosphate
17g Magnesium Sulphate
0.5g Ascorbic Acid
0.2g Potassium Sorbate
5g Chelated Trace Elements
500ml of boiled and cooled water
Dose 5ml per 50L daily. This may need to be tweaked to suit your tanks needs.
Link to support formula
Also Obviously with this formula you will also need additional Ascorbic acid and Potassium Sorbate
Note: I have not tried this method myself as I prefer EI
Setting Up Your Equipment
Ok so you have your equipment and fertilizers and your ready to go!
First thing first, we need to remove the Horn on your Fire Extinguisher.
Don’t worry this is perfectly safe as long as you leave the safety pin in.
You will see that’s its held on by a big nut, use a spanner to loosen and
Now with the Horn safely removed, its now time to bolt on your Regulator to the fire extinguisher. Remember leave the safety pin in whilst you do this.
You want to do it up nice and tight but NOT TOO TIGHT or you will damage your regulator.
When your done you should have something that looks like this.
Now its time to pull that safety pin out!
Pull the handles together as if you where going to fire the extinguisher and use cable ties and duck tape to hold them together permanently.
(Some Fire Extinguishers will simply allow you to put the pin back in with the handles in the closed position removing the need for cable ties and tape)
You will notice that the dials on the reg have now moved displaying your FE pressure.
Now is the time to check for leaks. To do this simply add water and washing up liquid to a bottle and shake vigorously until you get a froff. Add some of this froff to the thread where the Regulator has been bolted onto the FE and onto the dial stems.
If you have a leak this should be plainly visible as you will see bubbles bubbling up.
If you do have a leak and need to remove the regulator then cut the tape and cable ties holding the handles together. DO NOT ATTEMPT TO REMOVE THE REGULATOR WITH THE HANDLES IN THE CLOSED POSITION!
Here is a useful video demonstrating fitting a Regulator
Ok regulators on and we have no leaks, happy days
Now get your bubble counter and fill it 2 thirds of the way up with water and decide where you want it.
Ideally you want it near your FE or in plain sight when you are by your FE.
Measure out and cut a length of CO2 tubing that will reach from your regulator and bubble counter comfortably. Then fit the tubing to your needle valve and bubble counter. This is very easy to do, both the Reg and bubble counter on the shopping list have tightening nuts which will secure the hose tightly in place.
Now cut that hose in the middle and add a non return valve to stop fluid running into the regulator. You don’t want to damage it now!
Make sure you fit the non return valve facing the right way.
Also CO2 tubing can be very hard to push valves onto. To get around this simply soften the ends of the tubing by placing them in boiling hot water.
This will make the tubing pliable and easier to work with
You should have something like this.
With that complete its now time to repeat that process but between the bubble counter and diffuser. Make sure you measure out enough length of CO2 tubing to reach from the bubble counter to the diffuser. This piece will also need a non return valve half way along to stop fluid traveling up from your diffuser into your bubble counter.
Now you should have something like this…
If you’re going for an inline Diffuser or a Reactor, connect this to your filters output hose now.
If you have opted for an atomizer or ceramic diffuser, now is the time to place it in your aquarium.
All that’s left to do now is set up your Drop Checker and the Electric Timer for your Regulators Solenoid (in shopping list)
You want the timer to switch your regulator on 2 Hours before your lights come on so the CO2 Levels get to 30ppm before lights on.
And you want the timer to switch off 1- 2 hours before lights off as there should be enough dissolved gas in the water column to see the last couple of hours out.
DON’T RUN YOUR CO2 THROUGHOUT THE NIGHT.
Plants reverse at night absorbing O2 and give off CO2, so if you pump in more CO2 at night, chances are you will suffocate your fish. A simple electronic timer will prevent this and keep your CO2 levels under control.
Now there is already an article here that goes into a lot more depth than I plan too so it might be worth a read.
Hold your Drop Checker upside-down and add a little 4DKH solution along with 3 drops of Bromothymol blue.
Once you have done this slowly turn it around until you have it up the right way
Being careful not to drop any liquid!
The Drop Checker must be emptied and filled with fresh 4DKH and Bromothymol blue weekly for accurate readings.
With that done, now place in your aquarium. I like to place it at least 4 inches from the top of the water, opposite end to you diffuser (or filter output if using an inline)
This fantastic bit of kit will tell you just how much CO2 is in your water column.
BLUE = NOT ENOUGH CO2
LIME GREEN = 30ppm CO2, PERFECT!
YELLOW = TOO MUCH CO2
Please note, the drop checker will take 2 hours to react and change colour to your waters CO2 levels
Achieving That Perfect 30ppm CO2
Everything’s set up, regulator is switch on, drop checker is in and you’re ready to go.
Very slightly turn up your needle valve and watch your bubble counter.
Depending on the size of your tank, to start with I would say aim for one bubble per 3- 4 seconds (If you have a large tank 200ltr+ I would say up this a bit)
Wait 2 hours then check your drop checker.
Turn the needle valve up a little more to one bubble per 2- 3 seconds then wait another 2 hours.
Remember drop checkers take 2 hours to respond and change colour.
Carry on repeating this until your drop checker is a nice lime green (30ppm)
Be patient, this can often take a couple of days to find the sweet spot.
Once you achieve this 30ppm, leave the Regulators timer and needle valve alone.
Avoid turning the CO2 up down up down up down. This is what’s known as the yoyo effect and it will give you algae outbreaks without a doubt.
Get the levels right with the right amount of ferts and you should never get algae.
With the above said, in the future as your plant mass becomes more you may need to up your CO2 slightly. Also remember the more water surface agitation you have
the more CO2 you will use, so air stones are not really a good idea with CO2.
You want a little surface agitation, but not too much!
When it comes to High Tech tanks whether you use liquid carbon or inject pressurized gas, a good amount of flow is always a good thing.
Good flow ensures even distribution of ferts, CO2 and eliminates “dead spots”
It also makes life a lot harder for algae!
A good rule of thumb is 10X turn over of the total volume of water in litres.
Let’s say for argument sake that we have 260 liter tank.
260 Liters will need a turn over of 2600 Liters per hour (LPH)
We must minus your filters output..
So lets say this 260L tank is filtered by an external putting out 1000LPH, we are 1600lph short of our targeted 2600LPH
To get around this we simply add a 1600PLH powerhead or a Hydor Koralia
A 1600lph Koralia + 1000lph filter output = a total of 2600lph for a 260L tank.
Get this right and your plants should gently sway in the current.
Remember, an extra powerhead should always compliment the filters flow, not work against it. This can take some playing with to get right.
Well I think that’s it.
If iv missed anything or if you have any questions or if you don’t agree with something iv put then please leave a comment and let me know.
I hope this has helped you or given you a greater understanding on CO2 Injection Ferts and Flow…..
Otherwise this has been a complete waste of time lol