# Co2 ppm and drops per second question



## ropate (Mar 12, 2009)

Hi all...

ok, this may be a silly question, but I'm a noob.

I have a 50 gallon tank with a ph of 7.4 and a kH of 4 degrees. I've just set up my Co2 system and was wondering how i know what by bubbles per second ratio would be to raise my Co2 ppm to 20ppm??

any advice very muchappreciated!


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## rjfurbank (Jan 21, 2008)

A good way to monitor this is w/ a drop checker (do a search on these and you will see many variations and lots of discussion on their use). I use the one made by Red Sea:

http://www.thatpetplace.com/pet/group/11110/product.web

You can put this in your tank and infer the approximate CO2 level by the color.

Also, a good rate to start w/ is 1 bubble/second. There is debate concerning whether to run the CO2 constantly or to have it turn on w/ the solenoid only when the lights are on. I do the later and haven't had any problems.

Good luck!

-Roy


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## ropate (Mar 12, 2009)

Hi Roy,

Many thanks for that. I've got a bubble counter attached directly to the solenoid as well as a drop checker already inserted in the tank. Although, I think I pu too much of the ph solutin in it as the liquid is quite dark, but it is a dark blue.

I've taken your advice and started on 1 bubble a second an will see how I go. Very excited to see what the results will be.

Cheers
Rob


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## rjfurbank (Jan 21, 2008)

Hey Rob,

Glad you have a drop checker--it is not perfect but if you use 4kH water in it consistently you should be able to get a good relative measure of the dissolved CO2 in the tank. It shouldn't matter how much pH solution you have in it as long as you can discern color changes from blue to green to yellow. In fact many people use more as a rule I believe to help w/ this.

I would suggest slowly increasing the CO2 until you get a light green color in the drop checker. Do this slowly--over the course of a few days--and if you see the fish get stressed back off. You can actually use higher levels and I have run mine into the yellow color with no ill effects on the fish.

Many people believe consistency of the CO2 is important in limiting algae growth so I try not to adjust mine once I have it set where I want it.

Good luck!

-Roy


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## abcemorse (May 28, 2008)

Bubble sizes and rates vary somewhat, also depending on reactor/diffuser efficiency and surface agitation, but I would expect around 4-5 bps to be a ballpark target, but fish and plant reaction are your best measuring tools.


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## Fishtory (Jan 21, 2009)

abcemorse said:


> Bubble sizes and rates vary somewhat, also depending on reactor/diffuser efficiency and surface agitation, but I would expect around 4-5 bps to be a ballpark target, but fish and plant reaction are your best measuring tools.


So if the pH drops by .2 when you increase bps by just one fraction.... if I were to increase my bps to 4 (or 5) my pH would drop to some crazy number like 3! I think.


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## chagovatoloco (Nov 17, 2007)

My 10 gallon is at 2 bps. No I don't think your ph would drop to 3, but watch the fish and when bumping up co2 do just a little at a time.


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## ropate (Mar 12, 2009)

thanks all....its been running for a few days on 2 bps and no drastic change in the drop checker colour nor in plant health. So will increase to 3 bps tomorrow and see how it goes! thanks for the help.


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## Amazon_Replica (Nov 24, 2007)

Don't forget to change your drop checker indicator solution every 2 weeks or so. And you really should only use enough drops of bromothymol blue (ph test reagent) to turn the liquid an even blue. Not too light or dark. Usually 2-3 drops.


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## ropate (Mar 12, 2009)

thanks for that Amazon, I didn't know that! Shall do!


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## ropate (Mar 12, 2009)

last quick question....should I place the diffuser beneath my filter outlet? its next to it at the moment in bubbles going to the surface, but i guess if its under the filter then bubbles will be blown around the tank!?


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## cbwmn (Dec 18, 2007)

I bought some DC's on Ebay and some certified 4KH & indicator solution from Greenleaf. 
I'm somewhat disappointed with the setup.
I started a thread about CO2 levels indicated on the color chart.
The three colors are blue which indicates low CO2, green which is 30ppm 
(must be an estimate), and yellow which is high CO2.
I can actually get a closer CO2 reading using my test kits and a CO2 chart.
Some answers on that thread said that there are other factors which cause a faulty CO2 reading and 4 KH with a DC is more accurate. 
But blue being not enough CO2 and yellow being too much CO2 is not very accurate in my line of thinking. 
Also, the GLA indicator solution does not turn the 4 KH dark enough for me to check it in the tank. I have used 6-8 drops and it's not dark blue at all.
I still use the 4 KH but I went back to the cheap indicator solution that came with the DC's.
Charles


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## rjfurbank (Jan 21, 2008)

Yes--you can put the diffuser below the filter outlet--I think many people do this.

Also, when I was using a diffuser I actually put it below the filter inlet and ran the bubbles through the canister filter--this worked well and the filter acted as a CO2 reator and dissolved the CO2 before ejecting it back into the tank.

After my diffuser broke I just ran the CO2 tube directly into my filter inlet. This worked (and I have read many other users here doing the same thing). The only problem I had was at higher CO2 flow rates the canister would occasionaly "burp" CO2 that was accumulating in the canister (and hence not being dissolved).

I am now using a CO2 reactor (the AquaMedic 1000) which I have been pleased with and has solved this problem.

There are many threads discussing how to best dissolve CO2 in planted aquariums--do a search on this site and there is much valuable discussion/research.

Good luck!

-Roy


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## ropate (Mar 12, 2009)

cheers Roy!!! Will let you know how i go, the beetle is now under the filter outlet and had to drop by bps rate as the PH checker showed a drop with so much more circulaton of Co2....all stable now it seems.


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## Amazon_Replica (Nov 24, 2007)

Good to hear


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