The more I know, the less I know.

Tug

Lifetime Charter Member
Lifetime Member
Jan 5, 2009
1,150
9
38
Washington, DC
Honestly, light and fertilizer are much more intuitive. CO2, KH, GH, pH are special.

I'll try to answer this one,
hbosman;53002 said:
So, adding more KH2PO4 would probably reduce the ph?
I had the answer to this as a subscribed thread but can't seam to find it. Basically, it forms a mild acid and the pH will drop a little with PO4 levels over 10ppm.

Dutchy - a lot of biologist still get it wrong. Often they are the ones telling people to raise the KH when adding CO2 to water with low KH. Ranting about solubility at higher KH and lower KH holding less CO2. I would love to know just what they are talking about and when/were their logic has merit. CO2 has so many relationships with the water it is hard to know how they join together into a simple understanding. For example, when CO2 drops the pH it doesn't seam to effect fish, but can CO2 drop pH to 5 if we are only adding 30ppm. What then?

Feel free to add your favorite CO2 folklore. :cool:
 

Tug

Lifetime Charter Member
Lifetime Member
Jan 5, 2009
1,150
9
38
Washington, DC
This is like trying to review the events from the previous night after a bar crawl.

So I guess what I would like from you old salts are some laws of common sense, not so much what a thing is, but when it's a cause for concern (real or imagined) and/or what is a cause to rejoice, e.g. my tap water has a GH of 10 and.... What do you think? So, unless pH is totally meaningless it must raise some sort of flag.
Please pick one or two, or add your own.
Tug's first two laws of planted aquariums,
  1. Tom Barr is right
  2. If your analysis of the facts appears to show that Tom Barr is wrong, see #1.

Where the life is easy
[video=youtube;Brw-u4bm0FY]http://www.youtube.com/watch?v=Brw-u4bm0FY[/video]
 
Last edited by a moderator:

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
745
113
So, adding more KH2PO4 would probably reduce the ph?

Not significantly. It would a tiny, iddy biddy bit.

Not enough to throw off the chart much(maybe 1ppm).

Regards,
Tom Barr
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
745
113
ismenio;53005 said:
Thanks to all of you.

I have finally understand, i must use a drop checker with a 4º dk solution.
Must forget the co2/ph/kh chart since there is on the water other compounds that will alter the results.

Thanks

Well, yes and no.

The trade off with the drop checkers, I'm not the biggest fan of those.....is yoiu lose a great deal of pH accuracy.
The trade off with the pH/KH chart, you lose some certainty, and it can be a lot as well, in the KH system.

So neither is the best way to ensure CO2 is good.
There's no easy answer for CO2, hence therein lies the problem.

You can use the pH/KH chart to get a certain "CO2 estimate", but it will NEVER be higher than this measure, only the potential to be lower.
From there, you can check with the drop checker.

If neither of these has nice results, you are okay. Problem is, there's plenty of folks where that is simply not the case.
They assume the CO2 is fine, then go about looking for nutrients as the root of the problem. They virtually never look at or measure light intensity.

This is a big problem to convince folks it is CO2.
Even well seasoned aquarist still fall for the nutrient trap.

What do I do?

1. I use a mix of these methods, I'm always looking for new and betetr way to add CO2, to make it as well mixed and responsive as possible to make sure th ereading is representative wherever I take the measure.
2. Once I get to the pH/KH range, I then go on a leap of faith. I very slowly adjust the CO2 maybe 1/30th of a needle valve turn each 3-4 days a watch closely and wait. I do this till the plants look really nice, every species is growign well etc, and the fish have no behavioral changes/stress.
3. I make sure that the current is high for the fish and to prevent build up of CO2(steady rate of degassing), and to ensure good high consistent O2.

This slow methodical increase of CO2 works very well for those more experienced/careful.
It also holds some extremely useful information that is missed if you happen to dail the CO2 in too fast/impatient: when you are watching the plants, you can see which one respond to the slow increase the best, you note the effects of a slight decrease/increase in CO2 on plants and algae. Often it's fairly dramatic even with minor changes. This is highly useful because you will almost certainly see some of these minor to major changes as CO2 moves around and declines in the future, this way.........you know what to look for and know it's just a minor tweak of the CO2.

This is a huge help FYI.

Once I get to a nice CO2 dose, I'l go back and measure well with the pH/KH, and use the pH as a relative measure. Say the plants are pearling and looking good, fuish happy etc, no algae, the pH is 5.8 and the KH is 3.........I'll just know to keep it there, and not really care, need to know what the actual CO2 ppm is or not. The plants/fish/lack of algae are the test kit.

I can also take out a nice CO2 meter and measure this and see what the CO2 is throughout an entire day data logged at each 15 min interval.
This cost a bunch of $$$. But........it's very useful and we have a nice aquarium as a reference.

Using all this info to help folks get a tank they can call a reference helps.
There's no one single method I use for CO2. I suggets it be investigated much closer and in depth.

I have to wonder why so many accept CO2 and the methods so readily and then scrutinize nutrients so harshly.
Light even gets much more criticism. This is true in research also.

Regards,
Tom Barr

Regards,
Tom Barr
 

ismenio

Lifetime Members
Lifetime Member
Mar 3, 2015
3
0
1
Jesus, CO2 is a big trouble !

Well, i don´t now what to say, the co2/ph/kh chart is always on the safe side, the drop checker is most realistic, but the light can make all go down toilet.

But is funny so much test and equipments and in the end we just look to the fish to see if they look fine and we don´t have algae.

Tests what for ? To make waste money and time !

Every day i like more EI, thanks Tom.
 

ismenio

Lifetime Members
Lifetime Member
Mar 3, 2015
3
0
1
I just remember, is better update the EI article, with this problem, just to remind to not believe on co2 chart or drop cheker.
This is truly important, i think.

Regrads
 

Wet

Lifetime Members
Lifetime Member
Aug 25, 2006
395
0
16
USA
[quote="Plantbrain]...
I very slowly adjust the CO2 maybe 1/30th of a needle valve turn each 3-4 days a watch closely and wait. I do this till the plants look really nice, every species is growign well etc, and the fish have no behavioral changes/stress.
... I make sure that the current is high for the fish and to prevent build up of CO2(steady rate of degassing), and to ensure good high consistent O2.
... Often it's fairly dramatic even with minor changes. This is highly useful because you will almost certainly see some of these minor to major changes as CO2 moves around and declines in the future, this way.........you know what to look for and know it's just a minor tweak of the CO2.
[/quote]
I just wanted to reiterate that even with the best tools (which I do not own), I think this the best approach to most anything in this hobby. It reads like a pain in the ass to folks who are looking for some fast resolution -- the same folks who would prefer relying on a kit -- but it's really not. Change the mindset for a moment and remember we're dealing with plants and animals. And take the time to enjoy them. The experience gained from this slow, methodical approach will get you plus plants and happy fish. I can guarantee this.

The only note I would add for the intermediate aquarist is, once you've gotten the algae down and the plants happy and lush with Tom's steps above, try that species you failed with before. It doesn't matter if other people say it's easy or whatever; just try stuff that died or never looked good in your tank during your early days. You'll likely find that it's these plants that will become your most reliable CO2 indicators. So reliable that in the future you'll have more confidence in devoting three weeks watching these plants than you will with any test, and that confidence will apply to most any troubleshooting you'll have with this hobby, because this approach encourages you to *know* your plants.

Ultimately, there's only three levels of CO2 that matter:

1) Not enough: Algae, high reliance on watching macro levels, light, plant mass. Likely the root cause of any tank with poor plants.
2) Enough: Good-to-great plants and you can move on to technique and other funner stuff.
3. Too much: Dead fauna. Risk mitigated by going s l o w .

CO2 is indeed the hardest technical thing in this hobby. But remember it's not any number you're chasing. You can apply the above to most any tank with most any thing -- it's the plants and animals you care about.
 
Last edited by a moderator:

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
745
113
Wet;53098 said:
I just wanted to reiterate that even with the best tools (which I do not own), I think this the best approach to most anything in this hobby. It reads like a pain in the ass to folks who are looking for some fast resolution -- the same folks who would prefer relying on a kit -- but it's really not. Change the mindset for a moment and remember we're dealing with plants and animals. And take the time to enjoy them. The experience gained from this slow, methodical approach will get you plus plants and happy fish. I can guarantee this.

Yea..........but there's always plenty who simply will not read this and ignore it and think they know better and break the rules.
They will suffer and then blame EI or some other factor that is not related to the source root problem. But.......there is hope......the more folks who do listen and figure this out.........the more folks they can help to do this method etc.
So you can test and measure, or do the eyeball slow methodical method, both can get you to the same place.......if you are careful and observant, do not make too many poor assumptions.

I dial things in good with the PLANTS, THEN GO BACK AND MEASURE REALLY WELL TO SEE WHAT THOSE CONDITIONS ARE THAT PROVIDE THAT GROWTH, OR WHERE THE ALGAE ARE DOING WELL.


The only note I would add for the intermediate aquarist is, once you've gotten the algae down and the plants happy and lush with Tom's steps above, try that species you failed with before. It doesn't matter if other people say it's easy or whatever; just try stuff that died or never looked good in your tank during your early days. You'll likely find that it's these plants that will become your most reliable CO2 indicators. So reliable that in the future you'll have more confidence in devoting three weeks watching these plants than you will with any test, and that confidence will apply to most any troubleshooting you'll have with this hobby, because this approach encourages you to *know* your plants.

Ultimately, there's only three levels of CO2 that matter:

1) Not enough: Algae, high reliance on watching macro levels, light, plant mass. Likely the root cause of any tank with poor plants.
2) Enough: Good-to-great plants and you can move on to technique and other funner stuff.
3. Too much: Dead fauna. Risk mitigated by going s l o w .

CO2 is indeed the hardest technical thing in this hobby. But remember it's not any number you're chasing. You can apply the above to most any tank with most any thing -- it's the plants and animals you care about.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
745
113
http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx

In this article from Tropica, they show the CO2 on the x axis and then Growth as O2 production on the Y axis. It is not a straight line, thus is is a non linear response of plant growth as we increase CO2.

This line is different for EVERY single species grown, the CO2 optima will be where that growth line flattens off, say 20ppm for Hydrilla, but say 40ppm for Tonina/S. belem, or maybe 25 ppm for Rotala.

It also changes as light changes, we all do not have the same PAR or PUR, so there's variation there as well. Any aquarist who thinks they know a lot about CO2 and plant response is welcomed to debate this topic fully. I think they will quickly find they know very very little. I have lots of questions myself, but I know what I do not know and what questions I'd like to know and can potentially answer.

So the more you know, the less you realize you know.
This is a truth that seems to occur often and not just with plants

Regards,
Tom Barr
 

Wet

Lifetime Members
Lifetime Member
Aug 25, 2006
395
0
16
USA
This is true, but once you're concerned about the difference in growth between 60-100% CO2, you're on to the more fun and interesting things, ie: "enough CO2". This isn't indifference or doubt between that change, it's in the world of technique and optimization. Plus-plus plants.

But if an aquarist has not reached this point -- ie: "Not enough", that aquarist cannot really troubleshoot anything, because isolating nutrients while limiting the biggest nutrient (C) is nonproductive. The spinning of wheels effect.

So, what I propose is that by thinking in these terms -- and reaching "Enough" CO2, any aquarist can extend the slow approach to reaching optimal CO2 without using expensive equipment or caring about chemistry. I'm not suggesting folks stop when the algae goes away. I'm suggesting they keep going unless the plants (no difference in growth, ie: 100% potential) or fish stop them.
 

evanluke

Lifetime Charter Member
Lifetime Member
Aug 21, 2009
14
0
1
Tug;53033 said:

Wow! Thanks for starting this thread. Lots of useful information here. I'd like to provide my two cents about pH Shock.

Back in the old days of the hobby, pH was the only thing they could measure. Now given better information and access to better tests we know that many factors can effect pH, so targeting a straight number (e.g. 6.8) is not the best tactic. If you choose to measure pH, once you get your reading and find that it is "low", you need to ask why the pH is low? If it is low due to nitric acid from fish waste, that is potentially harmful to fish. If it is low due to CO2 or tannic acids from driftwood, that is much less of a concern. The why is more important than the number.

Most experienced hobbyists nowadays test TDS (total dissolved solids) and attempt to acclimate fish very slowly to environments that are drastically different in TDS. They due this to prevent stress/damage from osmotic stress. It is very damaging for a fish to go from high TDS to low TDS too quickly. At the fish store I work at, the most frequent thing that people do to kill their fish is to not do water changes for months and then do a very large water change. We have very soft water out of the tap in our area (gH, kH ~2) so the rapid change in TDS often kills their fish and then they mistakenly form the belief that water changes kill fish.

What makes all of this very confusing, especially if you are trying to learn your information online is that given your approach to the hobby, certain topics can have drastically different "best practices." For example if you are keeping delicate fish in a "fish only" environment, you want your nitrate reading to be as low as possibly. But if you are keeping an EI style, high-tech planted tank you often take your nitrate above 20ppm with KNO3 with no consequences to even the most delicate livestock.
 
Last edited by a moderator: