struggling to find CO2 balance and water change clues?

ShadowMac

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Hello everyone,

I've been having a heck of a time finding the lighting and CO2 balance in my newest setup. I don't have much of algae problems to speak of, but growth is far from optimal in some plants, primarily those who are poor CO2 competitors, ie rotala macandra green, HC, pogostemon stellatus.

Today I changed the water towards the end of the day and noticed that my ATI light was at 18% power (on its way to OFF) when I finished and I still saw a great deal of pearling...pearling I do not see when the lights are up to their scheduled power of 40%. I know plants pearl very well after a water change, but could this be a clue as to how low I can set my lighting and still get good growth, or is this just a "happy" response from the plants only due to a water change.

I figured I would reduce the lighting further and will be able to back off the Co2, it has been stressing fish. Could I back off to say the 20% level I saw the pearling at after the water change provided I found a good CO2 level? The trimmed stems of the hygrophila pinnatifida were pearling very well at the 18%, the HC like I have not seen except with water changes.

Please share your thoughts on this. Thanks!
 
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Biollante

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Generally Safe for Inverts & Filters; Do Not Exceed 2-ppm

Hi Shawn,

Technically all pearling means is there is photosynthesis and O[SUB]2[/SUB] saturation.
:)

A couple of possibilities come to mind, beyond the obvious that the water change is introducing a good amount of oxygen.

  1. The plants with current CO[SUB]2[/SUB] could use more light.:)
    1. Conversely, you could reduce CO[SUB]2[/SUB].:rolleyes:
  2. Well into the photoperiod, 3 or 4-days after a water change add 1-ml of 3% Hydrogen peroxide per 5-gallon of water (do not do this if you are medicating the tank).
    1. If the plants begin to pearl, try it again 4-hours later (or the next day) with half the amount ([SUP]0.5-ml[/SUP]/[SUB]5-gal[/SUB]).
      1. If they pearl, 4-hours later (or the next day), try half as much again ([SUP]0.25-ml[/SUP]/[SUB]5-gal[/SUB]).
      2. If they do not pearl, 4-hours later (or the next day), add half again as much ([SUP]0.75-ml[/SUP]/[SUB]5-gal[/SUB]).
      3. At this point, the arithmetic is fairly simple, of course it can be taken any number of steps further, but… there really is not much to be gained.
    2. If the plants do not pearl go to step 3.
  3. You have high dissolved organic material.
    1. Test for that with PP (do not do this if you are medicating the tank) (this might cure what ails you, as well).
      1. 0.03-grams of KMnO[SUB]4[/SUB] for each 5-gallon of water reapplying as necessary until the water remains at least a faint pink for four-hours. Adding aeration is a good idea during test/treatment.
      2. If it required more than [SUP]0.1-g PP[/SUP]/[SUB]5-gal[/SUB] then DOC is a definite problem.

My PP recipe:
I like 1% solutions since each milliliter of solution is 0.01-grams (10-mg) KMnO[SUB]4[/SUB].
:(
  • 10-grams KMnO[SUB]4[/SUB] into 990-mililiters of distilled water.
    • In real life, I mix 10-g into 900-ml and “top-off” to 1-L.
    • Weighing is the most accurate way to measure water, but close is good enough.
  • Diluting 1-ml of the 1% solution with 9-ml of distilled water yields a solution that each milliliter is 0.001-grams (1-mg) KMnO[SUB]4[/SUB].
  • If you do not trust my calculations, Tug found a wonderful site run by the “Koi and Water Garden Society of Central New York” that has a PP Calculator.
  • To keep the numbers even I used 1.6-ppm, though up to 2-ppm is good.
  • If you think you have a parasite problem 2.0-ppm is a good number for the tank.
Biollante
 

ShadowMac

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Thanks Bio.

would the fact I saw photosynthesis occurring give a clue at the light level I need to get growth? I don't have a PAR meter and this ATI light packs quite a punch. Since I want to minimize CO2 stress, I need to minimize the light without going too low. I've tried ranges from 30%-60%, if I turn the light up I will get pearling, so I don't think the system is O2 stressed..all it takes is more light. But I don't want to overdo the lighting. Now i'm wondering if i've been undershooting it. Pearling is noticeable at 40-50% and of course increases with greater intensity.
 
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Biollante

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Quantitative vs. Qualitative

Hi Shawn,

Yes I believe what you saw indicates low light, if what you are looking for is optimum growth. There is nothing inherently wrong with plants growing without pearling. As this seems to be a concern of yours (and many others) I simply offer a way to “know.”
:)

You may well be correct, the system isn’t O[SUB]2[/SUB] stressed. In this case, O[SUB]2[/SUB] stress isn’t really the issue, though on the flip-side it could be a symptom. Given the other things, you have mentioned there is a lot to be said for knowing.
:)

The above method is simply the quantitative analogy to the qualitative method you are employing, without spending a ton of money on various electronic devices.

The above method may also add to your confidence in your quantitative analysis.
:cool:

Biollante
 

Squidly

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I've done several WC's at night (8-9pm) in recent weeks Biollante and noticed the plants pearling away like mad as if the lights were on. I could only guess as to what that all means, so I won't... :)
 

Biollante

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Just In Case This Was A Serious Reply, I Will Answer It As Such

Hi,

No need to guess,
:gw it means by use of large water changes you are maintaining highly oxygenated water and removing wastes from the system and there is enough light for photosynthesis to take place. I have many aquariums and containers that are ambient lighting only that pearl on big water changes. Some pearl anyway.

  • If they are “pearling” in low/no-light then
  • it is not “pearling” in the sense we misuse the word,
  • it is simply un-dissolved air (bubbles) trapped vigorous by mixing.:rolleyes:

Large water changes are an effective method of dealing with water quality. Not unlike the way rivers and spring fed lakes operate.
:)

Biollante
 
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ShadowMac

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trying to find the happy place

those tests seem worthwhile and will provide me with more information to make a an informed approach to getting the best growth. The HC hasn't been carpeting well and some issues are noticed from time to time, but nothing I can really put a finger on. I have decreased surface agitation as it was considerable in previous weeks and reduced CO2 this weekend to compensate for less surface agitation. Today I'm observing improved fish behavior and better signs of growth, ie pearling. Come on Bio, it is pretty when it pearls ;)

Since I have decreased surface agitation I will be aerating at night to enhance gas exchange.

I would like to know for sure, so I will complete those suggested tests to see what happens.
 

ShadowMac

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I made sure it was not trapped air...I witnessed the gas leaving the cut ends of a stem of hygrophila pinnatifida as well as damaged portions of HC. It was without a doubt "pearling"
 

Biollante

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Too each their own.

Hi,

I do not know if Squidly’s comment was serious or a sad attempt at a “gotcha.” :)

  • A couple of years ago I offended a bunch of people over “pearling.”:eek:
For most, it really doesn’t matter that we understand how things work, just that they do. I push buttons on my phone and I talk to whoever is on the other end…;)
[video=youtube;NRRnA6YF4KU]http://www.youtube.com/watch?v=NRRnA6YF4KU&feature=related[/video]

Pearling isn’t that big of a deal to me, I guess a little light pearling is nice.

In some cases, the pearling makes it look “sweaty.”

I also am aware that folks photographing their tank often like to do that the day after a large water change.

I am also aware some cheat, amazing what a shot of Hydrogen peroxide or a dose of Sodium percarbonate can accomplish.:rolleyes:

[video=youtube;k9e3dTOJi0o]http://www.youtube.com/watch?v=k9e3dTOJi0o[/video]

Biollante
 

ShadowMac

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Poor Mr. Beedle...beatle..

i didn't consider that squidly's response may have been sarcasm...

oh well...

I guess my conundrum has been what light level is enough to get growth and are there clues I can go by without buying a PAR meter, which essentially is what you have provided above in your first post. Today the tank looked good, but one day doesn't translate to much. A week or two will tell the truth of it.

Thanks for your help as always, Biollante.

Cheat with photos!? :O never! who would do that?!

I often forget that most of the photos we see are poor representations of what is to be reasonably expected. For the most part, i compare growth in my tanks to each other especially when they contain the same plants. For example, the HC in my 12 gallon is doing superbly while the HC in the 48 is doing poorly. S. repens in 7.5 gallon and 12 gallon doing great...48, poorly. So something is going on with the 48 that isn't with the others. Flow is ample, i have a large filter and an MP10...that leaves CO2 and light. I had hoped that the water change pearling was evidence I could reduce lighting substantially and focus primarily on CO2 for a similar result. However, no matter how much I try without a water change that kind of metabolic activity doesn't occur in my plants until the light gets around 40% power.
 
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Biollante

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Hi Shawn,

We also have to consider the possibility that the plants, the system are simply telling you what they need.
;)

So much of the balance, I think Tom Barr said this well in Robert H’s podcast this past week, is the balance in how well various plants compete for CO[SUB]2[/SUB] and light.

Really, this is what we are doing as we inject CO[SUB]2[/SUB], choosing the levels and how much light in relation to the plants we pick.
:)

While the internet is a wonderful resource, I think the level of deception, often passed on by well-meaning folk, sometimes self-serving, sometimes just nasty is incredible. At least the expense and accountability of magazines and books tended to ameliorate the content.

For all the test equipment I have gotten, I really do not think test equipment or test kits are particularly important. I think what you are doing, gaining experience and coming to understand your plants, critters and systems, subjectively that is qualitatively, is for more important to your success.

I think it is far better to spend your money, not to mention time and effort on the plants critters and quality equipment rather than PAR meters and sophisticated equipment.

A PAR meter is nice but US$200,buys a lot of plants.

Most of what you need or want to know quantitatively can be learned by use of a few basic chemicals and household items that are cheap and readily available, or can be arithmetically found.
  • Most of us can measure pH with our fingers accurately enough for most of our purposes.
  • A piece of soap can tell you about the makeup of your water.
:cool:
Biollante
 

Squidly

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I wasn't trying to be sarcastic, I was merely mentioning the observation I had and thought perhaps pearling has something to do with the difference in surrounding gas and the energy stored in the plants. But then, that's why I grew algae until recently. Sorry for any confusion!
 

ShadowMac

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No worries squidly! :) Luckily my problems haven't grown algae, just poor growth in some species.

Bio, I've definitely improved a lot in my abilities as a an aquarium keeper. Balancing fish and plant species has made it a longer process than if just focusing on one of the two. What you said is spot on, the CO2 hogs in my tank are the ones doing the best. I need to get things to work for the ones who do not compete as well. I'm getting closer and closer.
 

Squidly

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If this helps, I struggled to find the proper Co2 level for my 100g tank for several years. I'd been given the advice from someone much wiser than me, to drop the Ph level 1 pt. down from the base starting Ph, and go down from there until the fish got queasy. Although I found the desired level with relative ease after a few attempts with knowledge, I could never maintain that Ph level consistently until I installed a Ph controller.

As the much wiser Biollante mentions, this is another piece of equipment, and the plants are much more interesting to look at. In my experience however, had I made the controller purchase first I would have saved me a zillion bucks by now as I killed a lot of plants! (well the algae did...). Now, no matter how many plants I add, or how much the surface is exchanging Co2/o2, the controller compensates automagically. Works great, as long as your probe is accurate...
 

Tom Barr

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Biollante;80891 said:
Hi Shawn,

We also have to consider the possibility that the plants, the system are simply telling you what they need.
;)

So much of the balance, I think Tom Barr said this well in Robert H’s podcast this past week, is the balance in how well various plants compete for CO[SUB]2[/SUB] and light.

Really, this is what we are doing as we inject CO[SUB]2[/SUB], choosing the levels and how much light in relation to the plants we pick.
:)

While the internet is a wonderful resource, I think the level of deception, often passed on by well-meaning folk, sometimes self-serving, sometimes just nasty is incredible. At least the expense and accountability of magazines and books tended to ameliorate the content.

For all the test equipment I have gotten, I really do not think test equipment or test kits are particularly important. I think what you are doing, gaining experience and coming to understand your plants, critters and systems, subjectively that is qualitatively, is for more important to your success.

I think it is far better to spend your money, not to mention time and effort on the plants critters and quality equipment rather than PAR meters and sophisticated equipment.

A PAR meter is nice but US$200,buys a lot of plants.

Most of what you need or want to know quantitatively can be learned by use of a few basic chemicals and household items that are cheap and readily available, or can be arithmetically found.
  • Most of us can measure pH with our fingers accurately enough for most of our purposes.
  • A piece of soap can tell you about the makeup of your water.
:cool:
Biollante

Well put.

Thanks
 

Tom Barr

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Squidly;80895 said:
If this helps, I struggled to find the proper Co2 level for my 100g tank for several years. I'd been given the advice from someone much wiser than me, to drop the Ph level 1 pt. down from the base starting Ph, and go down from there until the fish got queasy. Although I found the desired level with relative ease after a few attempts with knowledge, I could never maintain that Ph level consistently until I installed a Ph controller.

As the much wiser Biollante mentions, this is another piece of equipment, and the plants are much more interesting to look at. In my experience however, had I made the controller purchase first I would have saved me a zillion bucks by now as I killed a lot of plants! (well the algae did...). Now, no matter how many plants I add, or how much the surface is exchanging Co2/o2, the controller compensates automagically. Works great, as long as your probe is accurate...

I've struggle in some tanks, other tanks I simply got plumb lucky.
My old 120 Gal was a son of gun.........never really was able to master the CO2.
My old 20 Gal? Did not matter what I did it seemed, it was easy.

Nanos and larger tanks = hard to strike this CO2 balance.

Why?
What about 1 tank versus another makes them all that different in terms of success?

The best rational and possible solution I found was stable CO2 loss and stable CO2 input.
With my old 120 I had a lot more degassing occurring and it varied.
Filter was the same etc, light etc etc...........

So what was different really?
The over flow. My 180 had no issue either, that tank is easy also.

With several tanks, all with the same sediment, same tap water, same dosing, same relative % biomass coverage, similar algae eaters..........measurable PAR..............not much else is really left.
the talk on the podcast might help some folks, I took the time to discuss this, as the 1st meeting in person I ever had with Robert was back in the mid 1990's in San Jose on his tank.

He had very little O2 and flow , but could not add more CO2 without gassing his fish, the CO2 I had at my tank was 2x this amount, this led me to speculate more about O2.
George Booth had done this as well independently.

He had low light and moderate CO2, around 20ppm. We both had wet/dry filters, and I was adding 30-40ppm.
He blamed it on the altitude in Colorado:)
But I had more light, so I needed more, and more ferts etc as well, jut made sense.

I used a step wise approach by adding more and more DIY yeast CO2 bottles and changing them more often.
That, along with flow made a huge difference.

ADA is really consistent with CO2 placement and most of those tanks lack much livestock and they maybe sacrificed before getting the CO2 right.
I am pretty much dead certain those tanks are eyeballed, not measured for CO2. They also seem to adjust the lights up higher than many other folks.
Flow and diffusers are placed at specific places in most all the displays.

pH controllers only work on the assumptions of the user.
Degassing and response to the degassing did not fix some tanks I tried that approach on.

If I set the absolute CO2 dosing based on pH/KH chart, then I may be way off base. If I use a controller as a relative measure based more on the plants...and I make sure to calibrate the pH probe routinely.........then it could be useful.
But if I need to dial in a specific pH, I simply do this with a pH meter. Then......the needle valve is stable, and the time I add CO2 is only about 8 hours anyhow........so there's some build up, but not that much.
 

ShadowMac

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I've found using a pH controller to be unreliable. I think the buffering capacity of the tank changes over time, so I would need to constantly fiddle with it anyways. I've had more success with a steady rate administered over a given time period.

Currently I have a few suspicions on this tank. The first one being a higher level of degassing that, as you said Tom with your 120, varies. I have altered my outflow pipe to decrease agitation while still getting a smooth ripple across the surface. I am also aerating at night now to break up the bio-film that develops as the week progresses. I suspect this will allow for better exchange at night and decrease the stress felt by fish from CO2 as well as improving plant respiration.

I am glad this doesn't require testing, I don't like to test and often question the measurement anyways. It is crazy the myriad of responses about testing I get when posing some questions other places. My eyes and what i've learned here from the experienced has always been a better guage than test kits or charts.

Unfortunately I have to rely on what I see on the internet and my own interpretations of what I see, hear, and read. I have never seen a planted tank like the ones we run here at The Barr Report anywhere but my own home. Learning from in person observation would be invaluable. I hope to eventually make it to some event where I can do just that.
 

Squidly

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For what it's worth and not to beleager Tom's sound advice and all the rest (for which I WISH would've worked for me!), I've used several Ph meters including the really inexpensive ones on EBay from China and another from a US distributor which were as you found, unreliable. Fortunately, even without an accurate meter by which to compare, all you need is one that is consistent as I found and a bad one is easy to spot due to fluctuations. I used my eyes first as most suggest, and then saw where the Ph was at and used it as a reference. If the Ph is stable throughout the week/month, then it's likely the probe and 'my level' are in check. It's taken many weeks to arrive at what "I think" is the most Co2 I can inject daily. I calibrate once a month which seems a small price to pay.

I can save the $400 for a PAR meter because I know I'm not limiting Co2 nor food, and therefore pretty much put the T5 light at any reasonable height without causing a BBA outbreak. Where I was worried about having any growth prior, now I have to figure out how to limit it (with light) so as to limit the amount of growth vs. the plant colors and vitality.

Life could be worse, at least in the planted tank world... :)