Diy Co2

[MarineMoney]

Hi,

I've a 40Gallon planted tank, sand substrate unfortuntely...not the best for plant roots in my experience. However my plants are sustaining but not flourishing, so im thinking about giving a DIY CO2 unit a try. .I'm aware that I may need to use two bottles for enough co2 production as my tank is a fair size.

I know what I need in terms of equipment, im going to go for the soda bottle technique but am worried about possible PH crashes....I know that a home system might not produce masses of co2 but how likely are PH crashes? If I keep the co2 at a constant rate will this minimise the chance of a PH crash?

I've got some delicate fish, ones which ive had for a few years and I really dont want to get this wrong! Also the PH has always been pretty high for the fish, my mum used pure coral sand unknowingly in her tropical tank when I wasnt living at home and when i returned we transferred her fish in to our new aquarium, i thought it best to transfer a portion of coral sand aswell as new substrate into our new tank to avoid a massive PH drop for the fish...so my point is a crash to PH 4 or 5 from 8 would be a complete disaster.

Also this may sound like a stupid question, but where should I place the bottle in relation to height to the tank to ensure successful transport along the pipe and into the aquarium?

Do I need a check valve on the pipe or can I go without one?

Alot of questions I know but I like to be prepared for every possibility.

thanks

 

[SuperColey1]

Ph crash will not be caused by CO2 unless your water KH is at an extreme level.

Most CO2 tanks experience around a 1Ph drop with CO2 and those of us using pressurised with a solenoid have a Ph that rises at night and falls in the day. Mine will be 7.2 when the CO2 starts and 6.4 when the CO2 ends.

Not a problem to my fish at all nor others.

AC

 

[MarineMoney]

Ph crash will not be caused by CO2 unless your water KH is at an extreme level.

Most CO2 tanks experience around a 1Ph drop with CO2 and those of us using pressurised with a solenoid have a Ph that rises at night and falls in the day. Mine will be 7.2 when the CO2 starts and 6.4 when the CO2 ends.

Not a problem to my fish at all nor others.

AC

Okay, so correct me if I'm wrong, but the higher the KH levels the less likely I am to have PH crashes due to the buffering quality of KH.
Havent tested for KH in a while, but I assume that if I have low KH levels and want to add co2 I might need to use bicarbonate soda or crushed coral shells/sand to stabilise them while running a co2 unit? Im not new to keeping fish but I am to co2 use so want to get my head clear about the relations co2, kh and ph have with eachother before I go ahead and set this thing up.

Thanks

 

[SuperColey1]

I'm not sure on how high or how low the level of KH can be a problem at as it is not something I've needed to research so I will leave that for someone else to explain rather than hazard a guess and risk causing problems

Someone 'in the know' will explain this for you within the next day or so I would expect. Shouldn't be a worry for 95% of people but best to find out if you are in the 95% or 5% first

AC

 

[aaronnorth]

dont worry about ph crashes, i know a few people who run tanks with 0dkh! Having a lower kh means that the ph will drop lower when injecting CO2, for example:

Both tanks have 30ppm of CO2:

tank A has ph 7, kh 10 - this pH may only drop to 6.4

tank b has ph 7, kh 4 - because of less buffering capacity this ph may drop to 6.2.

So as you can see you will never get to the point when the pH drops to something like 4 as the bicarbonates produced by CO2 will not drop it enough.

 

[MarineMoney]

Thats good to know!

I always get panicky about trying new things on my aquarium as I dont want to cause any detrimental effects for my fish. I have set up my diy co2 and i am getting a bubble per second. Im really apprehensive about the fact that i have to leave it on at night...if i run two airstones will that be sufficient enough to dissipate the co2 build up during the night time?

I tested my tank before the co2 and my KH is 12, my PH was 8..its always been about that so a gradual slight decrese wont hurt at all considering that its a community aquarium.

Maybe i'm over worrying, but I care for my fish! lol

thanks

dont worry about ph crashes, i know a few people who run tanks with 0dkh! Having a lower kh means that the ph will drop lower when injecting CO2, for example:

Both tanks have 30ppm of CO2:

tank A has ph 7, kh 10 - this pH may only drop to 6.4

tank b has ph 7, kh 4 - because of less buffering capacity this ph may drop to 6.2.

So as you can see you will never get to the point when the pH drops to something like 4 as the bicarbonates produced by CO2 will not drop it enough.

 

[aaronnorth]

one airstone will probably be sufficient, turn it off 2hrs before lights on to allow CO2 levels to build back up again

 

[MarineMoney]

Ill do that, im going to run air at night and not during the day to allow the levels to build up to sufficient standard as you said.

Thanks

one airstone will probably be sufficient, turn it off 2hrs before lights on to allow CO2 levels to build back up again

 

[sjdriscoll]

Just something I'd thought I'd mention as it has been a Godsend to me - I run 2 x 2litre bottles in tandem but was having to change 1 bottle out every 2 weeks or so, which i found a pain, along with the cost of the sugar.

Then I discovered Marmite! Someone on here mentioned it so I tried it and wow, a single bottle lasts about 5-6 weeks of constant CO2 using the same amount of sugar/yeast as before. just add 3/4 tsp to each bottle and you will really notice the difference.

Good luck

 

[MarineMoney]

Just something I'd thought I'd mention as it has been a Godsend to me - I run 2 x 2litre bottles in tandem but was having to change 1 bottle out every 2 weeks or so, which i found a pain, along with the cost of the sugar.

Then I discovered Marmite! Someone on here mentioned it so I tried it and wow, a single bottle lasts about 5-6 weeks of constant CO2 using the same amount of sugar/yeast as before. just add 3/4 tsp to each bottle and you will really notice the difference.

Good luck

Marmite, wow i've never heard of that one before very interesting I might try and do some research on it.
The sugar use is unbelievable! I want to mass buy it just for the co2 production lol.

My co2 is going well, my ph was 8, and i got up during the night to check it and it was at 7.5, ive also tested it again mid afternoon and its sitting between 7.5 and 7.8 so not much swing at all. Fish look healthy, normal behavior etc and my co2 is bubbling away and yes im going to set up another bottle after 5 days alternate the two to get a steady stream of co2.

Thanks for all the help everyone.

 

[Schmill]

Just something I'd thought I'd mention as it has been a Godsend to me - I run 2 x 2litre bottles in tandem but was having to change 1 bottle out every 2 weeks or so, which i found a pain, along with the cost of the sugar.

Then I discovered Marmite! Someone on here mentioned it so I tried it and wow, a single bottle lasts about 5-6 weeks of constant CO2 using the same amount of sugar/yeast as before. just add 3/4 tsp to each bottle and you will really notice the difference.

Good luck

Surely all the marmite does is add a bit more yeast to the mixture?

 

[SuperColey1]

The problem with this theory of lasting longer is that is irrelevant how long the mixture 'produces' CO2.

You can leave the mix for weeks and it will produce, however you want the max output and once it tapers off then it wants changing.

Therefore with it taking a day or so to reach peak, staying on peak for a few days and then tailing off we change each mix weekly and use more than one bottle so that while one is in the tail off, refill and restart phase the other is at peak.

So forget how long a mixture is 'producing' CO2 and focus on how long it is at 'peak productivity'

AC

 

[MarineMoney]

The problem with this theory of lasting longer is that is irrelevant how long the mixture 'produces' CO2.

You can leave the mix for weeks and it will produce, however you want the max output and once it tapers off then it wants changing.

Therefore with it taking a day or so to reach peak, staying on peak for a few days and then tailing off we change each mix weekly and use more than one bottle so that while one is in the tail off, refill and restart phase the other is at peak.

So forget how long a mixture is 'producing' CO2 and focus on how long it is at 'peak productivity'

AC

I understand that. Ive setup my co2 and all is going well, my first bottle has been running for 2 days, im going to add the 2nd bottle in about another 3 days so making a 5 day run for the first when the 2nd has been introduced. However im not going to change the first bottle after day five, ill wait another 2 to make it seven and then do it that way. Atleast I think thats a decent method.

 

[sjdriscoll]

Please try the Marmite boys - you get max output in the 'weeks' range rather than the 'days' you talk about. The science is pretty straightforward in that the Marmite contains trace elements that the yeast actually need to really thrive - sugar just gets them going but to sustain growth and development they need more than sugar alone.

Anyway, the proof is in the pudding as they say! I really do have to only change 1 bottle out about every 6 weeks in the summer and about once a month in the winter. I sometimes have to run an airstone at night as my drop checker turns to yellow but apart from that no other problems.

Try it.

Steve