Help adjusting Co2

2950 Views 40 Replies 7 Participants Last post by elusive77, Apr 12, 2017

elusive77

Discussion Starter · Apr 11, 2017

I've had pressurized co2 for 3 months now. I have been trying to get it dialed in perfectly, but I'm having a really hard time doing it. I'm shooting for a 1 point drop in PH when the lights come on. It's easy enough to get it there, but when I do I find my fish gasping later in the day, and the PH has dropped 1.3 or more.

When I make a minute adjustment down, the PH only gets to a .7 drop at lights on and doesn't really go up throughout the day. I have the Fabco NV-55 needle valve, as it was highly recommended. I thought it was supposed to have really good minute controls, but that's not what I'm seeing.

Has anyone had similar issues in the beginning? Any tips for getting this dialed in?

BTW, currently co2 comes on 2 hours before lights and goes off an hour before lights out.

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clownplanted

· #2 · Apr 11, 2017

Here is what I suggest and what I had to do. Seems you are almost there.

Take a cup of water out of your tank and let it sit for 30 hours then take a ph measurement. That will tell you what your ph really is without any co2. Notice I said 30 and not 24 because that is how long it took my tank water in a cup to completely dissolve all co2 and show an accurate ph reading with no co2

What I am getting at is even though you may not be getting a 1 point ph drop you maybe be above the 30ppm co2 range because your co2 did not completely dissolve from the evening before. So do a ph/kh accurate test and that will tell you what your co2 level actually is. My guess is it's higher than 30ppm causing the fish to gasp for air

What I do is after my co2 is turned off I have a HOB filter and powerhead pointed at the surface that turn on which greatly helps with surface agitation dissolving the co2 faster. This way it should be close to dissolved by the time that co2 comes on. This was my issue and why I was not getting the 1 point co2 drop but my co2 level was 30+ppm. Also get a drop checker. Yes it has like a 2 hour delay but this will tell you if you have the right amount of co2 or not.

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elusive77

Discussion Starter · #3 · Apr 11, 2017

clownplanted said:
Here is what I suggest and what I had to do. Seems you are almost there.

Take a cup of water out of your tank and let it sit for 30 hours then take a ph measurement. That will tell you what your ph really is without any co2. Notice I said 30 and not 24 because that is how long it took my tank water in a cup to completely dissolve all co2 and show an accurate ph reading with no co2

What I am getting at is even though you may not be getting a 1 point ph drop you maybe be above the 30ppm co2 range because your co2 did not completely dissolve from the evening before. So do a ph/kh accurate test and that will tell you what your co2 level actually is. My guess is it's higher than 30ppm causing the fish to gasp for air

What I do is after my co2 is turned off I have a HOB filter and powerhead pointed at the surface that turn on which greatly helps with surface agitation dissolving the co2 faster. This way it should be close to dissolved by the time that co2 comes on. This was my issue and why I was not getting the 1 point co2 drop but my co2 level was 30+ppm. Also get a drop checker. Yes it has like a 2 hour delay but this will tell you if you have the right amount of co2 or not.

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I have done that....not for 30 hours, but 24 hours. It measured at 8.0 ph. Before lights come on I measure at 7.9. So not much difference.

I have tried using the ph/kh/co2 chart before but it isn't very accurate. It showed me with 15 ppm co2 before I ever added any. There is something else in the water that throws it off.

I have a powerhead running 24/7 pointed up to get good surface rippling. I was hoping this would help provide better oxygen exchange for the fish and help degass all of the co2 during the night.

And I do have a drop checker. It matches the measurements I see with my PH pen.

I'm just not sure why when I get a 1 point drop at lights on it continues to climb higher during the day. But when I make the slightest of turns on the needle valve, it goes down to .7 ph drop and doesn't change throughout the day. I'm hoping there is something I'm missing. Does working pressure make a difference at all? Should I keep the co2 lower and increase lead time before lights come on?

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clownplanted

· #4 · Apr 11, 2017

That may work but I feel something else is going on. How are you dissolving the co2 and how is the water flow in the tank? How many plants do you have in there?

The ph/kh chart should be very accurate. How are you accurately measuring your ph/kh? I see you said a ph pen but is it collaborated?

Also how many plants do you have and how are you dosing ferts and what kind of light? If any of the last two are limiting they may not be using enough co2 and why it could keep climbing. Remember your plants will only uptake what they can and if any limiting factor like light or ferts then co2 uptake by plants will be limited.

I would try another measure of measuring your ph/kh.

Also are you doing an accurate bubble count using your bubble counter? This way you know the adjustments you make are the slightest and accurate.

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elusive77

Discussion Starter · #5 · Apr 11, 2017

The co2 is dissolved using a Griggs reactor attached to the outflow of my canister. I have good flow now with the addition of the powerhead. My tank is pretty heavily planted. Here's a pic:

I have seen a lot of posts on here about the chart not being accurate. I use a ph pen that I calibrated. And it matches ph measurements using the api liquid test.

I have a planted plus 24/7 and a beams work led for my lights. I generally dose EI levels of dry ferts but I also test almost daily and modify my dose based on that.

I have a bubble counter but it goes way too fast for me to count. I've tried taking a video and counting in slow motion but that was difficult too.

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clownplanted

· #6 · Apr 11, 2017

elusive77 said:
The co2 is dissolved using a Griggs reactor attached to the outflow of my canister. I have good flow now with the addition of the powerhead. My tank is pretty heavily planted. Here's a pic:

I have seen a lot of posts on here about the chart not being accurate. I use a ph pen that I calibrated. And it matches ph measurements using the api liquid test.

I have a planted plus 24/7 and a beams work led for my lights. I generally dose EI levels of dry ferts but I also test almost daily and modify my dose based on that.

I have a bubble counter but it goes way too fast for me to count. I've tried taking a video and counting in slow motion but that was difficult too.

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See you running the powerhead on the surface during the day hitting the surface? Or is that just for at night? That will also speedily dissolve the co2. When you are just getting a .7 drop is that running at the same time as co2. Could explain why cannot get more than .7 drop.

I know that in my case running my powerhead like that disturbing the surface means a difference of going from 4bps to 9bps and getting same co2 level.
You really want to do as little surface disturbance with co2

Also what size tank is that? You typically will want between 2.5 to 4.5 bps but of course no tank is same. But if too many to count something is not right with the co2 getting into tank and or too much off gassing. I am at 4.5bps with my 60 gallon heavy planted using co2 reactor going through canister filter.

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Dman911

· #7 · Apr 11, 2017

The KH/PH chart is as accurate as the readings we are taking for both PH and KH the chart itself is accurate, its the variables that can be the problem with using it. Assuming we are accurately interpreting out tests we need to take into account the +/- accuracy of the test kit we are using. As some suggest you can get a more accurate KH test if you double the amount of water and add drops then calculate increments by.5 instead of 1. There is also the variable of other buffers in your water affecting KH that would essentially make the Co2 chart useless and this is why people use drop checkers with a known KH solution made up of only carbonates. Then there is the base equilibrium of Co2 in you water between 2-3ppm roughly. For approx. each 0.3 drop in PH our Co2 levels double, so assuming you have 3ppm is a safe bet because its the high end. 3ppm with a PH drop of 0.3 would be 6ppm, 0.6 would be 12ppm, 0.9 would be 24ppm and so on. This is where a good needle valve comes into play as the smallest adjustments at these levels can be deadly to our fish/shrimp etc.

What type of method are you using for Co2 injection? Some systems like atomizers and ceramic diffusers require a higher working pressure. I would recommend a working pressure just high enough for the method of injection being used.

Dan

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Dempsey

· #8 · Apr 11, 2017

elusive77 said:
I'm just not sure why when I get a 1 point drop at lights on it continues to climb higher during the day. But when I make the slightest of turns on the needle valve, it goes down to .7 ph drop and doesn't change throughout the day. I'm hoping there is something I'm missing. Does working pressure make a difference at all? Should I keep the co2 lower and increase lead time before lights come on?

Could it be that the .7 drop is your sweet for the tank right now? The drop checker is green, plants and fish are doing good? The more you add will just accumulate and accumulate during the day. All tanks are different in the amount of co2 the plants are taking in. Maintaining a 1 point drop on one tank will be much more difficult to maintain in another. Plus, maintaining that at such a precise number would be hard without a ph probe controlling your co2. Make sense?

I would be happy that you can maintain it at .7!

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Dman911

· #9 · Apr 11, 2017

Dempsey said:
Could it be that the .7 drop is your sweet for the tank right now? The drop checker is green, plants and fish are doing good? The more you add will just accumulate and accumulate during the day. All tanks are different in the amount of co2 the plants are taking in. Maintaining a 1 point drop on one tank will be much more difficult to maintain in another. Plus, maintaining that at such a precise number would be hard without a ph probe controlling your co2. Make sense?

I would be happy that you can maintain it at .7!

I agree 100% if all is good then no need to change it.

Dan

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vvDO

· #10 · Apr 11, 2017

I agree with Dempsey, your tank looks clean, plants look healthy. When I adjust CO2 levels I make very small adjustments and usually wait up to a week before I make another. You can increase the amount of CO2 by either opening up your needle valve or increasing working pressure since you are not using an atomizer.

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MCFC

· #11 · Apr 11, 2017

The KH/pH chart is half-decent, as a general reference, at best. According to it I'm running 132.5ppm CO2 and my fish couldn't care less...

I would say aim for the 1 point pH drop but adjust according to how your fish and plants are doing. If they both look good, why change it?

elusive77

Discussion Starter · #12 · Apr 11, 2017

Funken_A said:
DO you have a hang on back (HOB) type of filter with biowheels

Also Fabco needle valves suck. I bought 2 and replaced them with a much nicer dakota metering valve. Way better precision adjustment. I could not dial in a fabco to save my life. Way to touchy

I don't have HOB, just a canister. And I always heard people rave about the Fabco valves, so I thought they were one of the best. Is that not the case then? If there are better options I will consider them. I don't feel like I have any control.

clownplanted said:
See you running the powerhead on the surface during the day hitting the surface? Or is that just for at night? That will also speedily dissolve the co2. When you are just getting a .7 drop is that running at the same time as co2. Could explain why cannot get more than .7 drop.

I know that in my case running my powerhead like that disturbing the surface means a difference of going from 4bps to 9bps and getting same co2 level.
You really want to do as little surface disturbance with co2

Also what size tank is that? You typically will want between 2.5 to 4.5 bps but of course no tank is same. But if too many to count something is not right with the co2 getting into tank and or too much off gassing. I am at 4.5bps with my 60 gallon heavy planted using co2 reactor going through canister filter.

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I run it 24/7. I know it will off gas some during the day, which will mean having to add more, but I don't really care about that. Co2 is cheap. It improves overall gas exchange which means more oxygen in the tank for the fish. And it's a 36 G tank.

Dman911 said:
There is also the variable of other buffers in your water affecting KH that would essentially make the Co2 chart useless and this is why people use drop checkers with a known KH solution made up of only carbonates.

What type of method are you using for Co2 injection? Some systems like atomizers and ceramic diffusers require a higher working pressure. I would recommend a working pressure just high enough for the method of injection being used.

Dan

This is what I was referring to. If there are other carbonate buffers in the water, you can't use the chart to accruately gauge c02.

I'm using a DIY griggs reactor. So I don't think it requires much pressure. Is it better to keep the working pressure low then? I think I have it set to around 20 psi currently.

Dempsey said:
Could it be that the .7 drop is your sweet for the tank right now? The drop checker is green, plants and fish are doing good? The more you add will just accumulate and accumulate during the day. All tanks are different in the amount of co2 the plants are taking in. Maintaining a 1 point drop on one tank will be much more difficult to maintain in another. Plus, maintaining that at such a precise number would be hard without a ph probe controlling your co2. Make sense?

I would be happy that you can maintain it at .7!

This makes sense. The lower co2 rate equals the amount used by my plants plus the off gassing. When I go higher it just accumulates. In theory then, if I leave it at the .7 rate, but start the co2 earlier, I should be able to get that initial PH drop higher. But since the co2 rate still equals consumption, it shoud stay at the initial rate. Am I correct in my thinking here?

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clownplanted

· #13 · Apr 11, 2017

elusive77 said:
I don't have HOB, just a canister. And I always heard people rave about the Fabco valves, so I thought they were one of the best. Is that not the case then? If there are better options I will consider them. I don't feel like I have any control.

I run it 24/7. I know it will off gas some during the day, which will mean having to add more, but I don't really care about that. Co2 is cheap. It improves overall gas exchange which means more oxygen in the tank for the fish. And it's a 36 G tank.

This is what I was referring to. If there are other carbonate buffers in the water, you can't use the chart to accruately gauge c02.

I'm using a DIY griggs reactor. So I don't think it requires much pressure. Is it better to keep the working pressure low then? I think I have it set to around 20 psi currently.

This makes sense. The lower co2 rate equals the amount used by my plants plus the off gassing. When I go higher it just accumulates. In theory then, if I leave it at the .7 rate, but start the co2 earlier, I should be able to get that initial PH drop higher. But since the co2 rate still equals consumption, it shoud stay at the initial rate. Am I correct in my thinking here?

Not saying at all that you cannot disturb surface but can see how you would take that in my last post but just makes it harder to dial in if you even move the power head the tiniest. I know co2 is cheap lol but can make dialing in co2 a bit harder but does make sense as long as you account for the off gassing of course.

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Dempsey

· #14 · Apr 11, 2017

Yeah, you got it. BTW, Keep that power head where you have it. If anything, aim it higher for more o2 exchange. When we try to pump co2 in our tanks, we can't forget that we also need o2 and lots of it. Aim it so you have lots of ripples but try not to "break" the surface with splashing. The ripples will allow for o2 and less co2 off gassing.

Bump: I'll get a pic of mine in a few minutes for an example. Heck, look at Tom Barr's tanks.

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elusive77

Discussion Starter · #15 · Apr 11, 2017

clownplanted said:
Not saying at all that you cannot disturb surface but can see how you would take that in my last post but just makes it harder to dial in if you even move the power head the tiniest. I know co2 is cheap lol but can make dialing in co2 a bit harder but does make sense as long as you account for the off gassing of course.

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I understand what you mean. I used to run a HOB along with my canister and it did cause some extreme fluctuation as the HOB slowly clogged and flow changed. But I don't think my Powerhead is causing any fluctuation. When I leave the co2 at a certain setting, the PH drop is roughly the same every day. When I had it at the .7 ph drop, it got .7 every day, even when the water level lowered causing slightly more surface agitation.

And thanks Clown for all of your insight by the way. Thank you everyone for your responses. That's why I love this community. We can all come together and discuss issues and learn from each other.

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clownplanted

· #16 · Apr 11, 2017

elusive77 said:
I understand what you mean. I used to run a HOB along with my canister and it did cause some extreme fluctuation as the HOB slowly clogged and flow changed. But I don't think my Powerhead is causing any fluctuation. When I leave the co2 at a certain setting, the PH drop is roughly the same every day. When I had it at the .7 ph drop, it got .7 every day, even when the water level lowered causing slightly more surface agitation.

And thanks Clown for all of your insight by the way. Thank you everyone for your responses. That's why I love this community. We can all come together and discuss issues and learn from each other.

What's crazy and why I can say even the slightest in power head adjustment and water level for me makes a big difference. For example with my setup I have it dialed in to 4.5bps but after my last water change I absolutely maxed my water level to where I was getting very little surface agitation with my HOB and powerhead that come on at night that hits the surface. This made such a difference my drop checker was yellow and most of my fish were breathing heavy but not quite at the surface. Leads me to believe I still had quite a bit of co2 in tank from night before due to not off gassing near as much and so co2 was more heavy by the time the lights came on. Simply lowering the water the next morning all was normal and drop checker a good green and co2 at a good 35ppm. Before this I never knew it was this delicate lol.

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elusive77

Discussion Starter · #17 · Apr 11, 2017

MCFC said:
The KH/pH chart is half-decent, as a general reference, at best. According to it I'm running 132.5ppm CO2 and my fish couldn't care less...

I would say aim for the 1 point pH drop but adjust according to how your fish and plants are doing. If they both look good, why change it?

Really the only reason I care is because of algae. When I left it at a .7 ph drop I noticed an increase in GSA algae and some BBA. With EI fert levels and high light, co2 needs to be high as well. The plants are growing relatively well, but even though you might now see it in the pictures, there is algae on a lot of the lower leaves.

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Dempsey

· #18 · Apr 11, 2017

Sorry for the crappy pic. I had to resize it to email it to myself. Not to add to the confusion, but looking at your pic, this may be your whole problem. You may not be getting enough o2 for the fishies...

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clownplanted

· #19 · Apr 11, 2017

elusive77 said:
Really the only reason I care is because of algae. When I left it at a .7 ph drop I noticed an increase in GSA algae and some BBA. With EI fert levels and high light, co2 needs to be high as well. The plants are growing relatively well, but even though you might now see it in the pictures, there is algae on a lot of the lower leaves.

I agree that in a high tech setup if co2 is not optimal and your ferts and light are it can and will lead to algae. Since your plants will not be able to use as much ferts and light due to lower co2 the algae will show. This is why algae is a good indication if your co2 is not dialed in.

I noticed on mine since dosing EI ferts and my good light if my co2 was not at least 20ppm algae would start to appear. Why I now recently started turning on my co2 1 1/2 hours before lights come on to make sure I'm at 30ppm before lights come on. Works for me.

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elusive77

Discussion Starter · #20 · Apr 11, 2017

clownplanted said:
What's crazy and why I can say even the slightest in power head adjustment and water level for me makes a big difference. For example with my setup I have it dialed in to 4.5bps but after my last water change I absolutely maxed my water level to where I was getting very little surface agitation with my HOB and powerhead that come on at night that hits the surface. This made such a difference my drop checker was yellow and most of my fish were breathing heavy but not quite at the surface. Leads me to believe I still had quite a bit of co2 in tank from night before due to not off gassing near as much and so co2 was more heavy by the time the lights came on. Simply lowering the water the next morning all was normal and drop checker a good green and co2 at a good 35ppm. Before this I never knew it was this delicate lol.

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Yeah, that's what I noticed too when I had my HOB. The water levels made a big difference. I also had a crappy HOB that would clog every 5 days or so, which reduce the flow to drips. So it would go from low co2 loss when the water level was high, to high co2 loss as the water level dropped, and back to low co2 loss when the filter clogged. It was impossible. I don't see that kind of fluctuation with the powerhead though. I think the difference is the rippling versus splashing.

Bump:

Dempsey said:
Sorry for the crappy pic. I had to resize it to email it to myself. Not to add to the confusion, but looking at your pic, this may be your whole problem. You may not be getting enough o2 for the fishies...

Mine looks pretty close to that from the top. I'll try pointing it up even more and see if that helps the fish tolerate higher levels of co2.

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