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Discussion Starter · #1,781 ·
Bottom line, CO2 drop checkers suck eggs.

People rely and make way too many assumptions about them and their CO2 ppm's. Way way way too much.

Did I say way too much? :hihi:
 

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Discussion Starter · #1,783 ·
It works fairly well, but no better than the other methods I've suggested. If you can account for any KH differences between a reference and the tank, then you should be good to go with the pH meter and a good KH test method/meter and then use the chart.

For 2000-3000$, I'll stick with the method I have.
 

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Discussion Starter · #1,785 ·
:eek5: ..... never mind.

I plan on running reconstituted RO/DI water anyway, so I will know exactly what my KH is.
If it's 100% recon, then use the pH meter and measure the KH as best you can, eg Lamotte alk or a KH reference and meter, eg a Hanna etc.

Then apply the chart. That should give you 99%. Allow the pH to stabilize for 30-60 seconds.
 

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Tom is there an ideal kh you try to achieve?
I use ro/di and have constantly aimed to add baking soda to achieve 1 kh, but looking at the kh/ph charts , if i bump my kh up, it looks like more c02 will be dissolved. So in theory, if i don't adjust my c02, and bump up my kh, will this give me a higher c02 ppm, or will this also raise the ph and in turn need more c02 as well. Still trying to 'master' this whole c02 thing!! i think ive reread this entire thread 5 or 6 times and learn something new each time!
 

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Discussion Starter · #1,787 ·
Tom is there an ideal kh you try to achieve?
I use ro/di and have constantly aimed to add baking soda to achieve 1 kh, but looking at the kh/ph charts , if i bump my kh up, it looks like more c02 will be dissolved. So in theory, if i don't adjust my c02, and bump up my kh, will this give me a higher c02 ppm, or will this also raise the ph and in turn need more c02 as well. Still trying to 'master' this whole c02 thing!! i think ive reread this entire thread 5 or 6 times and learn something new each time!
No, adding more baking soda does NOT add more CO2.

Adding more CO2, adds more CO2.

Think about it.

KH or 1 perhaps even less is fine.

If you have a set rate of CO2 gas being added to the tank, say 500mls per hour, adding KH does not change the rate at which it's being added. We add CO2 for the plants to grow. We do not add it to change the pH directly.

Adding more KH just moves the pH higher, but does not change the CO2.
The rate of enrichment remains the same.

If I add 500mls of CO2 gas per hour to a 20 Gal tank with a KH of 10 degrees and this CO2 drives the pH down to 7.0, I'll have about 30 ppm.
If I add the same amount to a 20 Gal tank with a KH of 1 and push the pH down 6.0, I still have the same concentration: 30 ppm.

Ambient pH without adding CO2 for KH 10: about 8.0-8.2 ranges and for a KH of 7.0-7.2, same pH decrease and same CO2.

Many seem to think they can play with KH to get more CO2, not, this does NOT work. You add more CO2 to add more CO2. Adding other acids to artificially decrease the pH also does not add more CO2. If you add say HCL or vinegar, this will destroy the KH=> HCO3 + H+(acid) => CO2 and H2O, but then the KH drops real fast.

Bottom line, add more CO2 if you want more CO2. It's so obvious many miss it :thumbsup:
 

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Thanks for explaining that, looking at those c02 charts gets a little confusing, and looks like, if you bump up the kh the c02 is increased, my assumption was this allows more c02 to dissolve, but your explanation makes more sense! especially in how ph probes work to control c02 levels. I think its time to invest in a more accurate ph test.

No, adding more baking soda does NOT add more CO2.

Adding more CO2, adds more CO2.

Think about it.

KH or 1 perhaps even less is fine.

If you have a set rate of CO2 gas being added to the tank, say 500mls per hour, adding KH does not change the rate at which it's being added. We add CO2 for the plants to grow. We do not add it to change the pH directly.

Adding more KH just moves the pH higher, but does not change the CO2.
The rate of enrichment remains the same.

If I add 500mls of CO2 gas per hour to a 20 Gal tank with a KH of 10 degrees and this CO2 drives the pH down to 7.0, I'll have about 30 ppm.
If I add the same amount to a 20 Gal tank with a KH of 1 and push the pH down 6.0, I still have the same concentration: 30 ppm.

Ambient pH without adding CO2 for KH 10: about 8.0-8.2 ranges and for a KH of 7.0-7.2, same pH decrease and same CO2.

Many seem to think they can play with KH to get more CO2, not, this does NOT work. You add more CO2 to add more CO2. Adding other acids to artificially decrease the pH also does not add more CO2. If you add say HCL or vinegar, this will destroy the KH=> HCO3 + H+(acid) => CO2 and H2O, but then the KH drops real fast.

Bottom line, add more CO2 if you want more CO2. It's so obvious many miss it :thumbsup:
 

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i understand better now! thanks tom! gonna go home and test this out.
my ph is normally around 6.8 and kh is 2-3. guess i'll be aiming for 6.4 ph!
 

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Discussion Starter · #1,790 ·
I think many people have issues with CO2, not fertilizers.

Why? Because myself and most others have all had the same issues.

Unless the person was not adding ANY ferts or was way way off or missign one or two specific ferts, it's rare that's the problem.

Co2? It's almost a daily occurrence.

"My drop checker is always green"

So what, who can tell the difference between the pH change between 6.6 and 6.7?

2 hour delay response times are also painful, and the accuracy is really pretty poor. In the end, it's about as good as bubble counting per second etc.

KH may not be 100% guaranteed all carbonate alkalinity, but the pH can be adjusted for and is very accurate if you use say a Pinpoint pH meter.
Then use the Chart.

If the growth is stil l lack luster, you can slowly add a little bit more CO2 and adjust it once a week till the plants are really thriving. Do not adjust more than 0.1 pH between adjustments.

As you increase CO2 to the higher ranges, the relationship is not linear with CO2 ppm's, they increase for EACH pH step of 0.1.

Example:

Say you have a KH of 3 degrees.

At a pH of 7.0 you would have 9 ppm
At a pH of 6.8 you would have 14.3 ppm
At a pH of 6.6 you would have 22.6 ppm
At a pH of 6.4 you would have 35.8 ppm
At a pH of 6.2 you would have 56.8 ppm
At a pH of 6.0 you would have 90 ppm

Differences between each 0.2 pH units:
5.3 ppm
8.3 ppm
13.2 ppm
21 ppm
33.2 ppm

So your pH measurement and observations need to be very good when you use more CO2. If you over do things at the higher ppm's, it only takes a little bit of change to dramatically increase the CO2.
This is one reason why many people fail when adding more CO2 and gas their fish instead. If each 0.2 pH units were only 5 ppm difference, then it would be pretty easy to adjust CO2. This is also a good reason to buy a nice CO2 regulator, needle valve etc.
The high grade equipment for CO2, good filter and lighting, all well worth it.

Blowing 50-100$ for fert test kits? Not worth it.

Since many use the drop checkers and there's little differences between the colors and those color changes are at best, 0.2 pH, what does this say at the higher ppm's of CO2? Not much.

Or if they use colormetric pH measure? Similar.
A good 0.01 accuracy pH meter is likely the best relative measure for CO2 using pH.

I knock my pH down about 1.4 pH units. This is about 47 ppm.
If it went to 1.6, then I'm at 75 ppm's, if I back off just a hair, 0.1 pH units, then I'm about 1.5 pH units, I'm at 59 ppm. 1.3 pH units, 38ppm, 1.2 pH units, about 30 ppm.

Tweaking CO2 is not some simple thing. It's not something to just wing it and assume the drop check has to be correct. You need to be careful.
A good pH meter can help make small tweaks and adjustments.

The other problem with pH drop checkers: they are typically only targeting 30 ppm of CO2, but you might need more. Will you wait around to see if the pH changes 0.1 pH units with a drop checker? No one does that.
pH meter? You can do that easily.

Cost more, but far more accurate as a relative measurement.
 

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i may have asked and missed this before.. i tried to find it
but what kind of flow are you runign through this tank? and is it all through the main return or do you have flow modifiers such as a powerhead?

what size return outlet do you have?

hehe give me all your secrets!! muwahahahaha
 

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Why have ph controllers fallen out of favor in recent times?

They seem to be a useful tool for dialing in these thresholds... what am I missing?
 

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Jse hard to tell from the ones on the left I believe its some kind of Erio? and the ones you marked on the right are downoi. Speaking of which if you ever have any extra Tom please sell me some downoi and staurogyne(if your even still growing these), im currently looking for some!
 

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Discussion Starter · #1,797 ·
The monte carlo Micrantherum is growing in nicely.

Mini A reineckii is doing well. Dwarf riccia on the branch will be expanded here and there.

Removed the Fissidens branch on the far right side and replaced with a thicker Mini pellia branch. I'll add more as I harvest of can buy more of the mini pellia to fill that section in, the branch will fill in nicely, but it'll take a couple of weeks.
 

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Discussion Starter · #1,798 ·
Why have ph controllers fallen out of favor in recent times?

They seem to be a useful tool for dialing in these thresholds... what am I missing?
what happens if the KH moves from say 18 ppm to 40 ppm if your tap water and you do not catch it?

You'll end up with dead fish if the CO2 is already high.

Murphy can teach you many things. pH does NOT measure CO2, it's only part of it.
 

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Discussion Starter · #1,800 ·
Really? I would have assumed more flow to distribute through the plant beds
I know ur 180 used to be really high flow
I still have high flow in both tanks, but how the water movs is more specific.
The 180 still has the Vortech and the higher flow return(about 1000 gph or so) and the Vortech adds maybe 2000 gph of flow.

Also, these are deep dense plant beds, they are very shallow in the 120 Gallon, only 6-8 " tall for most groups.
About 2/3rds of the 180 is Starougyne, also, only about 3" tall average.
 
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