The Planted Tank Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
1,023 Posts
Discussion Starter · #1 ·
I just setup my pressurized Co2 about two days ago and I have noticed that my drop checker turns blue over night. I have my Co2 on a timer. I am used to Diy co2 in which my drop checker was always green.

Thank you for the help.
 

·
Registered
Joined
·
884 Posts
Are you using a certified 4DKH standard?
I run my Co2 24/7 so I can't answer from experience. But, in theory I would think that if you are using a timer then yes the permeability levels will drop overnight if co2 is not being injected. When the timer comes back on the levels will rise again, hopefully before the lights on.
Is it back in the green before lights on?
 

·
Registered
Joined
·
1,079 Posts
Co2 drop checker measures Co2. The 4dhk will change from basic blue color to green to yellow with the presence of Co2. It will change back to blue when there is no Co2.
 

·
Registered
Joined
·
1,490 Posts
Yees, drop checker is likely to change overnight if you shut off CO2 at night. If you run an air pump or have signficant surface agitation you will outgas even more CO2 over night.

So yes, drop checker will change back toward blue as CO2 dimishes when your system is off. The more surface agitation you ahve, the more you will lose and it is very possible to go all the way back to original blue overnight.

If you have the flexibitily, start your CO2 30, or 60 minutes before lights on to get some CO2 back before the start of photosynthesis.


No real worries whatever you do, this is just about optimization, not a problem.

Gooo luck.
 

·
Banned
Joined
·
1,086 Posts
I dug this up when i was going to start a similar thread.

My DC is more towards the yellow side by the end of the day. Come morning after the CO2 has been off for at least 10 hours it's still green with no sign of blue. If I take it out of the tank it will turn blue. Only one hole in a spray bar return breaking the surface. Tom surface skimmer on one of the XP3's.

All this CO2 and the plants grow like crazy but I can't grow a carpet plant and not have it get covered with BBA.

SteveU
 

·
Registered
Joined
·
9,100 Posts
If your fish and other livestock dont gasp, turn it up more. My co2 is on a timer with the lights and even during the day when its off the DC is still Yellow. :proud:

I dug this up when i was going to start a similar thread.

My DC is more towards the yellow side by the end of the day. Come morning after the CO2 has been off for at least 10 hours it's still green with no sign of blue. If I take it out of the tank it will turn blue. Only one hole in a spray bar return breaking the surface. Tom surface skimmer on one of the XP3's.

All this CO2 and the plants grow like crazy but I can't grow a carpet plant and not have it get covered with BBA.

SteveU
 

·
Registered
Joined
·
9,100 Posts
Since the OP has gotten the answer to his question.

The fact that he gets BBA at the substrate would make one think he has plenty of light. Maybe not enough flow though. I used to have the same problem with my marselia minuta and sure enough if I cracked the bottle a bit the BBA would disappear.
 

·
Banned
Joined
·
1,086 Posts
Really my question was answered. I should have left off the part about the BBA since that just muddied my real question. My thought was the DC was inaccurate since it wasn't turning back to blue once CO2 injection was off.

Back to the BBA just briefly, no way it's lack of flow. There's an elbow on one spray bar pointing directly where I've tried several carpeting plants. So much flow the substrate is almost blown away.

I'll try mixing up a batch of either 5-6-7 dKH solution, maybe 6. I'd mixed 4 dKH myself before I purchased some and they both worked the same. It's pretty easy and quadrupling the sample for testing may bring accurate enough results for our purpose. Is there information somewhere that shows the CO2 concentration and color change for the various solutions?

Thanks
SteveU
 

·
Registered
Joined
·
10,732 Posts
Really my question was answered. I should have left off the part about the BBA since that just muddied my real question. My thought was the DC was inaccurate since it wasn't turning back to blue once CO2 injection was off.

Back to the BBA just briefly, no way it's lack of flow. There's an elbow on one spray bar pointing directly where I've tried several carpeting plants. So much flow the substrate is almost blown away.

I'll try mixing up a batch of either 5-6-7 dKH solution, maybe 6. I'd mixed 4 dKH myself before I purchased some and they both worked the same. It's pretty easy and quadrupling the sample for testing may bring accurate enough results for our purpose. Is there information somewhere that shows the CO2 concentration and color change for the various solutions?

Thanks
SteveU
It is all relative to the Ph/kh/co2 chart

http://csd.net/~cgadd/aqua/art_plant_co2chart.htm
http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html

Your drop checker gives you a fixed kH. Then the co2 causes a change in the pH of the solution in the drop checker, causing the brom blue to change color. So you use the standard pH indicator chart(can't print one, need the one that comes with a bottle of pH reagent, as your monitor and printer will vary from what was original) that came. Using the pH chart from the brom blue will tell you where you fall on the chart using the new kH.
 

·
Banned
Joined
·
1,086 Posts
Sorry I didn't mean what I said. Not a color chart. It's stated that 4 dKH turns to green at a certain CO2 level. Changing to 6dKH would mean it would take a higher CO2 concentration for the change.

What would those levels be for the 4-5-6-7 dKH solutions. I know these are all estimates but it's all we have to work with.

SteveU
 

·
Banned
Joined
·
1,086 Posts
Well once I did some more searching I could find that the DC will turn green at 6.6 pH when using 4dKH.
Without that the charts or calculator didn't do much.

From that it shows me it will turn green if I have...
4dKH = 30.143 ppm CO2
5dKH = 37.678 ppm CO2
6dKH = 45.214 ppm CO2

The problem is once it turns yellow you don't really know how far you've gone past yellow.

SteveU
 

·
Registered
Joined
·
10,732 Posts
Well once I did some more searching I could find that the DC will turn green at 6.6 pH when using 4dKH.
Without that the charts or calculator didn't do much.

From that it shows me it will turn green if I have...
4dKH = 30.143 ppm CO2
5dKH = 37.678 ppm CO2
6dKH = 45.214 ppm CO2

The problem is once it turns yellow you don't really know how far you've gone past yellow.

SteveU
THe point of upping your solution to 5 or 6 dKH is to make it so you are trying to achieve green, not yellow.
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top