First attempt at DIY CO2

Morning rate 50 bubbles in 60 seconds:
0.83 BPS

Messing with the spray bar orientation to get the best diffusion. Currently pointing straight down gets them stuck momentarily in a vortex.

2 hour progress:
59 bubbles per minute - 0.98 BPS
From ph 7.78 kh13 - Dissolved co2 6.5
To ph 7.47 kh13 - Dissolved co2 13.2

Currently using JBL test strips for KH but I’m happy it’s accurate enough to read that I’m somewhere between 10 and 15 degrees which means co2 ppm 10-15.

API master test kit plus GH KH are arriving tomorrow to compare.

Monitored the bps and ph every hour today and used the calculator as before to estimate co2ppm.

PH. CO2ppm estimate
7.78 - 6.5
7.47 - 13.2
7.32 - 18.7
7.24 - 22.4
7.20 - 24.6
7.13 - 28.9
7.09 - 31.7
6.99 - 39.9
6.98 - 40.8
6.96 - 42.8

42.8 ppm should be dangerously high, however after more reading I realise this probably isn’t a true reading. Other carbonates in the water skew this figure.

I’m not worried as 1 bps has remained constant all day and the fish are all cruising around happy as Larry, no surface gasping etc.

I now realise however I will need a co2 drop indicator to get a more accurate idea of the actual co2 ppm so one of those is on the way for Sunday.

Christmas came early today.
CO2 drop checker, master test kit and GH/KH kit all arrived.
It showed the limitations of the KH PH calculator estimation of co2.

Also, for me, it actually showed the relative value of a set of quick test strips as they take such a short amount of time and aren’t actually that far off what I’ve tested today.
KH was 11 rather than my estimate of 13 on test strips.

Below is the estimation based on tonight’s test results.

However the drop checker says different, after 3 hours to make sure. I am estimating I am actually around 18ppm based on the colour of the 20ppm solution?



Took the opportunity to test my tap water which came out at roughly 25ppm! So with a water change and filter clean due tomorrow I’m relatively ok with the 40ppm tank test. I want it lower though obviously so the Nitra-Zorb sachet is going in the filter tomorrow.

Results are as follows:

Second bottle added this evening, see if I can get the green brighter!

The spray bar diffuser is working better than I imagined, it actually looks like it produces smaller bubbles than a diffuser! If you look at the pic the larger bubbles are very obvious but the smaller ones are there and they only rise ever so slowly.
I have pointed the spray bar down which helps hold the bubbles down. Also there always seems to be an air bubble in the top of the bar, this must help diffusion. Sticking with it for now!

How are you sealing the airline in the caps? I always struggled with leaks until I bought the premade ones off eBay

Made the hole with a soldering iron slightly smaller than line, then ran it through while it’s still hot quick. That is probably air tight but to deal with the pressure I then put a bead of weatherproof sealant on the inside and out of the cap and smoother it over with my finger. Dries in 3 hours. Works well!
Only got one premade one on the water filter/ bubble counter bottle that I had from a BBS Hatchery kit.

essjay said:

That's good to know I just had visions of you finding a cracked tank.

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Sorted

Great! I've learned a lot. I like the idea of adding the co2 diffusers

Did the plants take off?
I just hate the idea of having to refill bottles with Co2 systems..even if its just once a month. I also am sort of out of it on homemade since a large aquarium would need more than soda bottles ..probably some 10 gallon container with thread lid. But then your buying gobs of yeast-lol.
I like to read of homemade stuff. Innovative. I just stick to hardy plants that do well.

Stan510 said:

Did the plants take off?
I just hate the idea of having to refill bottles with Co2 systems..even if its just once a month. I also am sort of out of it on homemade since a large aquarium would need more than soda bottles ..probably some 10 gallon container with thread lid. But then your buying gobs of yeast-lol.
I like to read of homemade stuff. Innovative. I just stick to hardy plants that do well.

Click to expand...

Update: Before.... to 7 weeks later.

Colour change is due to the increased surface coverage of the floating plants and the addition of peat granules in the filter in an attempt to soften it somewhat. (Which works - but if you want the colour of the tannins you can’t use a Nitrazorb bag with it)... anyway...

All the plants are growing well, faster than before. I had to trim the Vals right down as they were becoming too competitive.
I couldn’t say wether it is a direct effect of the CO2 as I have also been using root tabs and flourish - this has given one of the swords some nice colour. From what I’ve read keeping the co2 above 20 is beneficial though so I’ve stuck with that. I’ve also been trimming away the melting leaves adapting to submersion. All new leaves are solid.

It was a fun project to set up. Easy and quick to change bottles. Cheap to run, and in my 70 ish litres it easily keeps the co2 above 20ppm.

Couple of notes:

Providing you have reasonable surface movement - there is no danger of over supply. I stopped opening the release valve overnight, this kept co2 more stable throughout day, started the mroningand never went too high at night. Never touched 30ppm.

If you are struggling to achieve good CO2 ppm - reduce surface agitation (move flow output deeper, reduce aeration) and increase co2 contact time. Careful not to overdo it, watch the fish.

Changing a bottle every week was a bit of a faff. I settled on simply changing all 3 every 2 or 3 weeks depending on bps, all the guides I read state it evens out the level of co2 production but as any surplus was simply lost in larger bubbles it never caused an issue.

I also give the bottles a shake in the morning when feeding to re-jault them into production. (A tiny spin to get the water moving)

Well worth a try for tanks with surface area around <36”x12”in my opinion.
Next I will be trying a Citric acid setup.

Update - DIY CO2 - Citric Acid & BiCarb

I enjoyed messing with the Yeast DIY CO2 setup and got to a point where I could run a batch for 2-3 weeks per mix maintaining roughly 20ppm CO2.

Issues...
Output wasn’t great, and variable to say the least.

I soon got tired of swilling the bottles every morning to kick start production again as the ingredients settled.

Yeast viability was more important than I first thought. Use new yeast to start and keep it in the fridge, after a couple of months I would get a new pot.

Regardless of how well I premixed the yeast with warm sugar solution it still took a while to get going.

My spray-bar diffuser was inefficient, but that’s ok cause the whole point of the project was to use what I had.

My target for the next version of my DIY CO2 was to increase output, efficiency and reduce maintenance.

Citric Acid and BiCarb seemed to tick the boxes.

I bought a cheap kit off eBay for the pressure gauge, caps and valve.
Tropicas 3in1 diffuser is being used to increase efficiency and chase higher ppm.

Initial impressions... brilliant.
So easy to setup, gets working flat out straight away.
The pressure differential system works remarkably well. Only set it up the other day so time will tell how it lasts.
Currently running roughly 25ppm CO2 at 2bps.
I have bought some Riccia and moulded it round stones with hair nets to test the system and my plant growth capabilities in general.
Photos show current setup.
Excited to see how it goes and scales.

I thought the pressure differential system was genius ? The main issue I had with this system was the valve. They were very leaky. Is there a reason why you are using two? I invested in a brass needle valve which solved the leaky issues

mbsqw1d said:

I thought the pressure differential system was genius ? The main issue I had with this system was the valve. They were very leaky. Is there a reason why you are using two? I invested in a brass needle valve which solved the leaky issues

Click to expand...

It came with two surprisingly, the top one is simply a **** off valve that was included as a ‘free gift’ I guess the idea is you can shut it off with out having to guess to get back to your initial rate.
I’ll see how it goes but if it appears to leak or run out fast I will replace it ??