Mist Method CO2

[ricardo48]

HI Everyone.

I am having some mixed results using the mist method. I have my diy co2 hooked right up to my powerhead and I get a constant jet stream of fine co2 bubbles at almost 2 bps.

My tank looks completely saturated in fine bubbles everywhere.

Hard to tell if my plants are actually pearling or if the co2 bubbles are just stuck on the leaves?

What I find strange is my old co2 reactor gave me a PH of 7.1 which is about 30ppm roughly for my tank and my drop checker is lime green/yellow.

My mist method though is only give me a PH of 7.3 which is 20ppm at best of co2.

Is this normal for the mist method to not lower the ph as much as there is less dissolved co2? I would of thought the fine mist being fired around my tank would easily dissolve as the bubbles are almost micro scopic in size!!


Im just concerned as much as my tank looks like its pearling, im actually just seeing co2 bubbles on my plants and my co2 ppm is too low which will encourage algae.

 

[Markstanfill]

I have the same issue with the in tank diffuser method. I use a pressurized system with a ceramic diffuser behind my plants with its powerhead buddy. Personally, I dont worry about pearling anymore. I just mark my efforts with the amount of plant growth and algae growth. If my plants are making good strides, no signs of low nutrients, and Ive not got any algae problems except for those pesky glass dots, I feel as though Ive done fine. Just me tho. Dont worry as much about paper results, just let the plants tell you if things are fine or not.

 

[fort384]

Using pH to measure CO2 in a tank where you are using misting will not give you an accurate picture. The benefits of misting are that small bubbles of CO2 actually get trapped up under the leaves of your plants, allowing the gas to come into direct contact with the plant tissue. So, your plants are getting more CO2 than a pH test would indicate.

I used misting in my 29G tank for a time with a good amount of success, but elected to go back to a straight ceramic diffuser because I got sick of the water clarity issues that CO2 misting can cause.

 

[ricardo48]

Yes but inevitably you will get alot of dissolving if you mist as the bubbles are so fine they will get dissolved also?

 

[fort384]

Yup, but the co2 will dissolve more readily in a reactor. Are you using a calibrated 4dkh solution in your drop checker? At two bps using co2 misting should be more than adequate in any midsozed tank. Even if 20 ppm is your accurate dissolved co2 reading, that coupled with the co2 trapped under your plant leaves should be more than enough to curb algae growth and encourage great plant growth.

 

[ricardo48]

Well I have somewhat changed my setup now.

My inline pipe to my canister filter has a co2 reactor attached to it. I bubble my co2 into my inline pipe, it gets sucked up to my reactor and is whizzed around in there. Any excess bubbles get suckd out the bottom of the reactor and down into my canister filter.

They are then sucked through all the media there and eventually any remaining gas is fired out of my spray bar onto my plants. My powerhead also helps spread the mist.

Pretty effective co2 in my eyes yet im only just get 30ppm but that is with diy co2.

PH degassed tap water is 8.3....my tank PH is now 7.2 at best. ( 7.1 at night )


Seem ok?

 

[fort384]

What size tank is it? 30 ppm co2 is great for a diy system so long as it is stable. If it dips much below 20 ppm it could encourage algae growth. It sounds to me though like you have a good setup.

 

[ricardo48]

14 gallon tank.... You say that but when i used an internal reactor which I was misting into I was getting a PH of 6.9 which is like 50 ppm co2!!


Main problem lately is thread/hair algae growth. It is mainly at the bottom in amongst my pygmy chainsword leaves that cover the entire bottom of the tank.

Probably circulation issue as the current at the bottom under a grass of plants is alot less.

I have cut back my kno3 dosing as I was also told high nitrate can help this algae?

 

[fort384]

Yeah light and excess n or p are no good for hair algae. Of course the problem could be the opposite. If u are bottoming out on either n p or k, it can encourage excessive algae growth. I tend to think your algae problem is more closely connected to n or p issues, or lighting, and less connected to circulation in the tank. Hair algae will grow even in strong currents.

 

[ricardo48]

Yeh its just alot of the fish waste and detritus builds up on the bottom of the tank and I cant vacuum there as thats where all the chainswords are densely carpeted.

Was thinking this waste build up with poor current was limiting nutrients to those areas and the algae was taking hold.

Most notibly the hair threads seem to be mainly on the large stones of my laterite and nothing else. Maybe leeching the nutrients from that to grow?


I am EI dosing so very much doubt im bottoming out on anything, but excess N could be a factor as I am quite heavily stocked for a 14 gallon.

 

[fort384]

Do u have an N testkit?

 

[ricardo48]

No... dont test anything.... reason why im doing EI dosing to take away the need for testing.

I have cut my KNO3 dose in half for now to see if that has any affect. I add 5ppm three times a week and I have about 20 fish in my 14 gallon with 20% water changed twice weekly.

 

[fort384]

EI is a great system - but I would still check base line nitrate levels at a minimum once a month... especially in a small tank with a high stock level. My guess is in a 14 gal tank with 20 fish, you might be able to stop dosing N all together.

 

[ricardo48]

I suppose but as EI is basically ensuring you have more nutrients than needed I would rather not risk bottoming out. Im only adding 15ppm over course of a week which is not that much anyway.

Will cut it back for now and see the response from plants. I prefer the plants to tell me what they need than a test kit