CO2 reactor question

[gigahertz]

I have been trying to figure out what I am seeing in my CO2 reactor and I now have a theory. Let's see if you guys agree with me.

I have a CO2 reactor that is attached to a powerhead which pumps water into the reactor cylinder to mix the incoming CO2 and then the mixture exits at the bottom of the reactor cylinder. A very common design. My CO2 delivery is controled by a ph controler.

At the beginning of the day when the ph controler turns on the gas I would observe very little gas on the top of the reactor cylinder which tells me that the incoing CO2 is almost instanteously desolved into the water.

During the course of the day I would notice more and more of gas is slushing around at the top of the reactor. As much as 3 inches of gas will have accumulated by the end of the day before the lights go out.

I have always been puzzled by what I was seeing because the collection of gas would likely indicate that the CO2 is not desolving anymore into the water due to saturation which that does not make sense since the ph is stable within the preset range.

My theory is that it is O2 that is accumulating in the reactor. Since by mid-day the O2 level is at or close to saturation ( hence the pearling on plants ), the agitation of the water by the pump causes the O2 to esacpe out of solution inside the reactor. Since the water is already saturated with O2 it cannot desolve into the water so inside the reactor it stays until the lights go out and the O2 level drops in the water.

Does that make sense to you guys? :huh:

[simcb]

I have been trying to figure out what I am seeing in my CO2 reactor and I now have a theory. Let's see if you guys agree with me.

I have a CO2 reactor that is attached to a powerhead which pumps water into the reactor cylinder to mix the incoming CO2 and then the mixture exits at the bottom of the reactor cylinder. A very common design. My CO2 delivery is controled by a ph controler.

At the beginning of the day when the ph controler turns on the gas I would observe very little gas on the top of the reactor cylinder which tells me that the incoing CO2 is almost instanteously desolved into the water.

During the course of the day I would notice more and more of gas is slushing around at the top of the reactor. As much as 3 inches of gas will have accumulated by the end of the day before the lights go out.

I have always been puzzled by what I was seeing because the collection of gas would likely indicate that the CO2 is not desolving anymore into the water due to saturation which that does not make sense since the ph is stable within the preset range.

My theory is that it is O2 that is accumulating in the reactor. Since by mid-day the O2 level is at or close to saturation ( hence the pearling on plants ), the agitation of the water by the pump causes the O2 to esacpe out of solution inside the reactor. Since the water is already saturated with O2 it cannot desolve into the water so inside the reactor it stays until the lights go out and the O2 level drops in the water.

Does that make sense to you guys? :huh:


I am having the same thing.

I guess in this case its just that the co2 dissolving rate is slower that the co2 input amount. At least in your case it accumulates at the end of lights off. My Co2 reactor collect a lot of co2 at the top in 1hr after the co2 is turn on :( and the balls stop spinning.

Maybe i should also get a power head to do so.

[gnatster]

We had a discussion on the same matter on one of the larger plant related forums and pretty much came to the same conclusion thats it was O2.

[gigahertz]

That's what I was thinking until I did a test today. The result confirmed my suspicion that it is most likely O2 and not CO2 that is collecting on the top of the reactor.

What I did was I purged the collected gas from the reactor and then I turn on the gas supply ( wide open for a split second to fill the top 10% of the reactor). The incoming CO2 disolved into the water repidly. That tells me the gas that was collected on the top of the reactor was definitely not CO2 and the logical guess would be O2.

Another thing that I noticed was that the Reactor is almost gas free in the morning before light-on. That also fits into my theory since during darkness the O2 is being consumed by the living things in the tank which allows the O2 collected in the reactor to disolve back into the tank water.

Does all that make sense? :thinking:

[simcb]

We had a discussion on the same matter on one of the larger plant related forums and pretty much came to the same conclusion thats it was O2.

It think it couldn't be O2 for my case. I don't have high producing o2 plants currently. Only christmas moss and japonica....my tank is quite emtpy. Previously even when i still had my ricca floorings they are not bubbling. I still have the same air trapped at the top of the reactor after the co2 input is turn on.

However it might be possible that O2 is trapped inside the reactor if the water is already saturated with o2 it wouldnt dissolve easily. That would apply to most heavily planted tanks.

My Ph is 6.6-6.7 during lights on at the KH of 4

[gigahertz]

We had a discussion on the same matter on one of the larger plant related forums and pretty much came to the same conclusion thats it was O2.

Cool deal! Another mystery solved!

So having CO2 does not only make plants happy, it also keeps a reserve of O2 for the living things in the tank during darkness. :2thumbsup

[gigahertz]

It think it couldn't be O2 for my case. I don't have high producing o2 plants currently. Only christmas moss and japonica....my tank is quite emtpy. Previously even when i still had my ricca floorings they are not bubbling. I still have the same air trapped at the top of the reactor after the co2 input is turn on.

However it might be possible that O2 is trapped inside the reactor if the water is already saturated with o2 it wouldnt dissolve easily. That would apply to most heavily planted tanks.

It's strange that your Ricca did not pearl. What kind of lighting do you have? How tall is your tank? With the right amount of lighting and nutrients Ricca should always pearl.

Does the collected gas in your reactor disappear overnight?

[simcb]

It's strange that your Ricca did not pearl. What kind of lighting do you have? How tall is your tank? With the right amount of lighting and nutrients Ricca should always pearl.

Does the collected gas in your reactor disappear overnight?

Nope it didnt(i on co2 for 24/7). I am using 36w PL for my 2ft tank. The ricca on floating balls nearer to the lights bubbles. The floorings however didnt but is growing well. So i added another 36w PL and all the plants started bubbling.

A few days later i get the BBA outbreak, and started the h2o2 dosage. Later i remove all my ricca cause they trap debris easily and fouls the water and the extra 36w lights. Although the plants bubbles less, the algae also disappeared with additional help from 10 new yamatos i bought. I guess the ricca are very co2 hungry and deprive my other plants of co2. Previously The bba started growing on my japonica and spreaded to other plants. Now i cannot find any hair,fuzzy ,horse hair algae in my tank. They are like totally disppeared after the h2o2 treatment. But as for BBa i can find a little on one or two gravels.

edited:
I realise its the reducing flowrate of my filter + low reactor efficiency contributing to the algae outbreak in my tank. Improving the Co2 reactor helps alot in stunning the algae growth and the bba are slowly melting away. I am using the 3 balls green internal reactor from bioplast, took 1 one ball out the co2 bubble on top is almost cannot be seen even at 2bps injection and the 2 ball are spinning fast. Another thing to mention is i didnt dose fertilizter.

[gigahertz]

Nope it didnt(i on co2 for 24/7). I am using 36w PL for my 2ft tank. The ricca on floating balls nearer to the lights bubbles. The floorings however didnt but is growing well. So i added another 36w PL and all the plants started bubbling.

A few days later i get the BBA outbreak, and started the h2o2 dosage. Later i remove all my ricca cause they trap debris easily and fouls the water and the extra 36w lights. Although the plants bubbles less, the algae also disappeared with additional help from 10 new yamatos i bought. I guess the ricca are very co2 hungry and deprive my other plants of co2. Previously The bba started growing on my japonica and spreaded to other plants. Now i cannot find any hair,fuzzy ,horse hair algae in my tank. They are like totally disppeared after the h2o2 treatment. But as for BBa i can find a little on one or two gravels.

I see. That's one of the reasons why I dont like to grow carpeting type plants. It drives me crazy when food particles get trapped under the plants.

They look great but I don't think that they are ideal for a shrimps tank. Fish usually will eat up the food before the food sinks to the bottom whereas shrimps will not be able to find the food once it sinks to the bottom if it' s covered with plants.

I'm going to try the H2O2 treatment on algae if I get hit with an outbreak again. Did you lose any shrimps because of the treatment?
How much H2O2 did you add?

[simcb]

I see. That's one of the reasons why I dont like to grow carpeting type plants. It drives me crazy when food particles get trapped under the plants.

They look great but I don't think that they are ideal for a shrimps tank. Fish usually will eat up the food before the food sinks to the bottom whereas shrimps will not be able to find the food once it sinks to the bottom if it' s covered with plants.

I'm going to try the H2O2 treatment on algae if I get hit with an outbreak again. Did you lose any shrimps because of the treatment?
How much H2O2 did you add?

If you dose correctly according to the h2o2 post i wrote previously...you shouldn't lose any livestock. I tried dosing with CRS,cherries,malayan,2 boraras brigitte,1 Oto and yamatos in my tank. No casualty until now. However i must say some plants are weak against H2O2 treaments, H2o2 can kill some plants. For example, I killed all my ricca during that treatment :p .

[gigahertz]

If you dose correctly according to the h2o2 post i wrote previously...you shouldn't lose any livestock. I tried dosing with CRS,cherries,malayan,2 boraras brigitte,1 Oto and yamatos in my tank. No casualty until now. However i must say some plants are weak against H2O2 treaments, H2o2 can kill some plants. For example, I killed all my ricca during that treatment :p .


Ok I will do a search for your post, thx :)

[Lotus]

Yes, I have lost riccia to hydrogen peroxide, too.

The usual reason for black beard algae is a lack of CO2 when you have high light.

Our CO2 reactor used to get undissolved CO2 in it, and the reason was the sponge on it needed cleaning. We have since reversed the flow of the reactor, so the CO2 is drawn up through it, and broken up further by the powerhead. It seems to be much more efficient that way.

[Momotaro]

A few days later i get the BBA outbreak,

I am not surprised you suffered an algae outbreak. You doubled the total wattage over your 2ft shrimp tank by going from 36W to 72W. Adding the extra wattage and not increasing CO2 levels or fertilizing the aquarium was more than likely the culprit.

When you went back and reduced the lighting over the aquarium you provided less light for the BBA, and the BBA stopped thriving. When you removed the Riccia, you may have effected the CO2 level in the aquarium slightly, however, I believe the improved CO2 reactor helped raise CO2 levels and combated the BBA. H2O2 helped a bit, but the main solution was the increased CO2.

Not fertilizing during the onset of the BBA attack was also a cause. Good nutrient and CO2 levels are the best way to combat BBA and other forms of algae.

Mike

[simcb]

I am not surprised you suffered an algae outbreak. You doubled the total wattage over your 2ft shrimp tank by going from 36W to 72W. Adding the extra wattage and not increasing CO2 levels or fertilizing the aquarium was more than likely the culprit.

When you went back and reduced the lighting over the aquarium you provided less light for the BBA, and the BBA stopped thriving. When you removed the Riccia, you may have effected the CO2 level in the aquarium slightly, however, I believe the improved CO2 reactor helped raise CO2 levels and combated the BBA. H2O2 helped a bit, but the main solution was the increased CO2.

Not fertilizing during the onset of the BBA attack was also a cause. Good nutrient and CO2 levels are the best way to combat BBA and other forms of algae.

Mike

Yes i guess so. I increase the co2 along with the lighting somehow the algae still comes. I manage to reduce it lately with the help of yamatos. I seem them chewing on the BBA....got lesser these days. Thats if i dont feed them too much. Now only 10% of the plants still have some bba.