• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

New to Co2


13 Sep 2009
Hi there,
I come from north kent not far from swallow aquatics.

Can anybody help me out here

My Co2 is running from 1pm til 9pm and my lights come on at 3pm and go off at 10pm

Your help would be greatly be appreciated.

Basically I have been running the Co2 like this now for 2 days and the drop checker has not changed!
Please can you tell me what is going wrong.

I will post a picture of the drop checker as this is not clear
Hello and welcome to the forum

Are you getting any change in the colour of the drop checker?
have you got a ph pen so you can do a ph profile of the tank to see if co2 is going into and staying in the tank?
drop checker solution could be duff.
is co2 pressurised(fire extinguisher, disposable welding)or diy
how are you adding it to the tank
what filter?
which drop checker kit/solution are you using
have you looked in the tutorials section of the forum?
heres a few to get you started.
Many thanks for your reply.
There has been a slight change from blue to dark green but it has yet to change to light green.
I don't have a ph pen.
The co2 system that I am running is jbl.
I am adding this via the pro flora diffuser
The pump that I have got is the aquamanta epx 600
The drop checker solution 4dkh solution from aqua essentials
getting a colour change is a good sign that some co2 is getting to the tank. turn it up a little bit and check the drop checker tomorrow and see if its any closer to green/yellow. I would reccomend that you invest in a ph pen as it will allow you to get a much better idea of how much co2 your adding and what levels of co2 you have throughout the photoperiod, there can be a. 1-2 hour delay in the drop checker changing colour.
and good luck, good co2 is one of the hardest things to get right in a planted tank.
ideally the drop checker will be green/yellow at lights on and remain the same colour throughout the photo period.
just to give you an idea, my ph is 7.5 before gas on at lights on its ph 6 and remains at ph6 till gas off. at lights off its ph 6.5.
I don't use a drop checker at the moment because theres no livestock yet and co2 levels are quite high. when the tanks grown in a bit i'll reduce co2 and add a drop checker and make it safe for stocking
Hi there,

This is how fast my Co2 has been turned up to.
This has only just been turned up to this. Should I see the drop checker to green
By the way the tank size is 48length x24hight x18width.

Wow thats a much bigger tank than I first thought!
A couple of possible issues
Filter turnover wont be enough for a high tech tank unless you use powerheads to increase flow to around 10X tank volume
Co2 diffuser probably wont add enough co2 for a tank of that size and a 600g co2 bottle wont last very long on a 300l tank. I would recommend a 2kg fe setup minimum and a new up inline diffuser or diy reactor for a larger tank like yours
if all your plants are easy plants like the anubias and crypts in your video, you probably dont need to add carbon and could get away with reducing lighting levels until the time comes when you want to grow more demanding/advanced plants which require more light/co2
to reduce the cost of co2 refils you can use disposable welding co2 from halfords or machine mart there about £18 for 600g. most members use a 2kg fe but some with bigger tanks use 6kg pub co2. i use 6kg from local hydroponics shop, the cylinder cost £40 and refils are £16, much cheaper long term
The external filter is a aquamanta efx 600 and the flow rate on this is 2700 liters per hour and have a koralia 2100 that makes 4800 liters per hour. I do have a jbl 2 kg bottle. How long will that last for? The pipe work on this filter is bigger than 18/22 that it is on the eheim filters so I don't think a up line diffuser will fit! Everything I seem to do don't seem to be working. Do u happen to know in the south east if there is a hydroponics shops ?
Sorry to be a pain the hoses are 32 mm I have just had a look at the instruction booklet
My bad i thought filter was much smaller

If not any good google beer gas suppliers in your area
Not sure how long a 2kg would last on your tank but would guess 6kg would last 2-6months depending on how much you use and how efficient your system is ie leaks, diffusion method.

Unfortunately the up wont fit without a reducer which will restrict flow a bit
My friend uses a cheap 1400l powerhead feeding a full length spray bar with a small glass diffuser under the inlet. This seems to work very well
32mm hoses is that outside diameter.
I think you might have to experiment with diffusion methods until you find the best method for your tank and filter setup
Last edited:
Thanks for your help here.

Right so if I get one of these
MaxiJet Powerhead 1200 and a co2 glass diffuser and do away with the jbl diffuser as shown where should I place the spray bar? If I place this along the back of the tank,
I have a feeling that this will disrupt the flow of the filter and koralia.

How would u make a spray bar to fit this?

The drop checker has changed to green at long last. But the bubble rate isn't, a bubble a second! I would say it is roughly 6 or 7 or even 8
Most people place on the back wall and have all the outlets/powerheads on the back pointing towards the front glass in the same direction so they work together and against each other.
Bubble rates vary from tank to tank, even from bubble counter to bubble counter. My 60l cube uses 1 bps with a jbl counter but in the 35l uses about 3-4 bps with a jbl counter, so your 300l tank is 5x the size and could easily need uncountable rates to achieve a green/yellow drop checker, perhaps your diffuser will achieve the correct levels of co2 after all
Make a spray bar for your filter pipework you can buy acrylic fairly cheap from ebay
Heres a link to my friend dans journal you can see his pipework in the first pic on page 6
Many thanks once again for your response. At present I have been looking at different diffusers.
Can u suggest 1 for my tank?
Thanks for your help
Have you tried placing a simple cheap glass diffuser under the filter intake. I would try that first and if you can achieve a lime green drop checker at lights on without making the filter noisy thats the cheapest option then you can make an acrylic spraybar for your tank
Whats the inside diameter of your hoses?[DOUBLEPOST=1397814469][/DOUBLEPOST]http://m.ebay.co.uk/itm/201069032173?nav=SEARCH
You can get it cheaper but i didnt know what size you need
Last edited:
Hi sorry for the late response. Basically I have purchased a power head and also the spraybar last night off of ebay.

I will set my tank up like your friend Dan.

But I was just wondering what glass diffuser I would need for my size tank.

Thanks once again
Hi there again.

I have just ordered
TMC AquaGro Compact CO2 Diffuser 25mm
from aqua essentials together with the replacement diffuser disks.
Once I put this in I will upload pictures.

Thanks for your help Big clown

I know it needs to get lighter but it is getting there! Once I get the power head etc I will give everything a clean up and start over.