Update on My Tank
- Thread starter Weetabix
- Start date
Randy
I have a larger system now since going BB, so I have a larger skimmer and larger Calcium Reactor.
That is often the issue for many, especially if it is a single stage reactor and why single stage reactors where invented. Try and get yourself another container and fill it with more aragonite. Run the effluent through the second chamber, which will raise the pH and run the effluent if you can to the skimmer to try an"blow" off more CO2.
cee & Randy
I don't think you can lower the pH low enough to dissolve the aragonite w/o a massive die-off.
So, you have to have sub 7 ph numbers in order to break down the aragonite??? Kind of like an all or nothing type deal???
No, not really. In the sandbed the pH can get low enough where a very small tad of the sand will dissolve, releasing Ca++, HCO3- and CO3-- but not enough to have any impact on the tank. Lets try to put that in perspective and say enough of x sand, with y tank parameters, will dissolve enough sand to raise the pH over a month of 0.1 pH. 1/ 30 (days) = 0.03 pH / day. So, if you added nothing else and there was nothing changing that pH over the course of a day, other than the dissolving sand and the pH was 8.00, it would rise to 8.03 and take 30 days for it to get to 8.1 from that 8.00. And I'm probably giving it to much credit
Only cause I figured that if the pH were low, it would break down the aragonite sand and then raise the pH of the system
Yes to a point but has the sand dissolves in that local area the Ca++, HCO3, CO3-- will reach saturation and some of that will then preicp right out of solution (think of it like making new sand), pulling down some of that pH, Ca++ HCO3- and CO3-- . So, the net gain may be nil.
You can get a tad of sand to dissolve at a pH of 8 but the Alk and Ca++ must also must be low. Some examples of where sand **may start to dissolve with fresh exposed surface with the following parameters based on theoretical calculations.
pH = 7.7 Calcium = 410 ppm Alkalinity = 2.5 meq/l
pH = 8.2 Calcium = 340 ppm Alkalinity = 1.0 meq/L
If the Ca++ or Alk and any of these is higher the sand will not dissolve and if they drop lower more sand will dissolve. But in living breathing reef tanks we just really do not see this. I have seen tanks with the first one and have not seen what I would call any so called dissolution of sand.
Wee
Before I broke that tank down, I did have a new sandbed in it.
I wonder if that was affecting the PH.
Was the Ca++, Alk and pH falling ?
New fresh sand has a habit of causing Ca++ to precip out on the surface of new sand, which pulls down the Ca++, Alk and pH, until it reaches a state of equilibrium or become coated with films, such as bacteria. Many years ago ( 2 decades) 3 of us ran separate tests on various types of sand to see how they would buffer the pH, thinking the pH would rise or would not fall, thus the sand was buffering the water. To our surprise, all carbonate sands dropped the pH and one dropped it 0.5 pH in 1 week, where as silica sand dropped it only 0.1, as did the control a BB, where that .1 can be expected. The carbonate sand with the least impact was Puka shells and crushed coral was the worst. Then using old sand that had been well exposed to seawater, that sand, mo matter what kind, had little impact at all just like the fresh silica sand.
error
400 is close to outdoor CO2
Should have been 400 is close to indoor CO2
I have a larger system now since going BB, so I have a larger skimmer and larger Calcium Reactor.
That is often the issue for many, especially if it is a single stage reactor and why single stage reactors where invented. Try and get yourself another container and fill it with more aragonite. Run the effluent through the second chamber, which will raise the pH and run the effluent if you can to the skimmer to try an"blow" off more CO2.
cee & Randy
I don't think you can lower the pH low enough to dissolve the aragonite w/o a massive die-off.
So, you have to have sub 7 ph numbers in order to break down the aragonite??? Kind of like an all or nothing type deal???
No, not really. In the sandbed the pH can get low enough where a very small tad of the sand will dissolve, releasing Ca++, HCO3- and CO3-- but not enough to have any impact on the tank. Lets try to put that in perspective and say enough of x sand, with y tank parameters, will dissolve enough sand to raise the pH over a month of 0.1 pH. 1/ 30 (days) = 0.03 pH / day. So, if you added nothing else and there was nothing changing that pH over the course of a day, other than the dissolving sand and the pH was 8.00, it would rise to 8.03 and take 30 days for it to get to 8.1 from that 8.00. And I'm probably giving it to much credit
Only cause I figured that if the pH were low, it would break down the aragonite sand and then raise the pH of the system
Yes to a point but has the sand dissolves in that local area the Ca++, HCO3, CO3-- will reach saturation and some of that will then preicp right out of solution (think of it like making new sand), pulling down some of that pH, Ca++ HCO3- and CO3-- . So, the net gain may be nil.
You can get a tad of sand to dissolve at a pH of 8 but the Alk and Ca++ must also must be low. Some examples of where sand **may start to dissolve with fresh exposed surface with the following parameters based on theoretical calculations.
pH = 7.7 Calcium = 410 ppm Alkalinity = 2.5 meq/l
pH = 8.2 Calcium = 340 ppm Alkalinity = 1.0 meq/L
If the Ca++ or Alk and any of these is higher the sand will not dissolve and if they drop lower more sand will dissolve. But in living breathing reef tanks we just really do not see this. I have seen tanks with the first one and have not seen what I would call any so called dissolution of sand.
Wee
Before I broke that tank down, I did have a new sandbed in it.
I wonder if that was affecting the PH.
Was the Ca++, Alk and pH falling ?
New fresh sand has a habit of causing Ca++ to precip out on the surface of new sand, which pulls down the Ca++, Alk and pH, until it reaches a state of equilibrium or become coated with films, such as bacteria. Many years ago ( 2 decades) 3 of us ran separate tests on various types of sand to see how they would buffer the pH, thinking the pH would rise or would not fall, thus the sand was buffering the water. To our surprise, all carbonate sands dropped the pH and one dropped it 0.5 pH in 1 week, where as silica sand dropped it only 0.1, as did the control a BB, where that .1 can be expected. The carbonate sand with the least impact was Puka shells and crushed coral was the worst. Then using old sand that had been well exposed to seawater, that sand, mo matter what kind, had little impact at all just like the fresh silica sand.
error
400 is close to outdoor CO2
Should have been 400 is close to indoor CO2
cee
New member
Boomer,
Thanks for the clarification. I knew that inside a sand bed there was some dissolution of calcium and the carbonates with subsequent precipitation as I've seen it first-hand in my previous tank. I suspect this is probably from acidic compounds released by biological action in the bed, some of which can become locally "trapped". I just wanted to point out, as you did much more effectively, that your parameters would need to be quite a bit off for dissolution of any significance to occur from a sand bed.
Dave
Thanks for the clarification. I knew that inside a sand bed there was some dissolution of calcium and the carbonates with subsequent precipitation as I've seen it first-hand in my previous tank. I suspect this is probably from acidic compounds released by biological action in the bed, some of which can become locally "trapped". I just wanted to point out, as you did much more effectively, that your parameters would need to be quite a bit off for dissolution of any significance to occur from a sand bed.
Dave
You bet Dave
And yes, it is from biological action. In Petrology we call this "Early Marine Diagenesis ", where the sand seems to have "weld" itself together. In the hobby we call it "sand clumping", where are two forms more or less, "soft" clumping and "hard" clumping. The soft is a bacterial '" soft clue" and the hard is the "welding", where Ca++ combines with CO3--.
And yes, it is from biological action. In Petrology we call this "Early Marine Diagenesis ", where the sand seems to have "weld" itself together. In the hobby we call it "sand clumping", where are two forms more or less, "soft" clumping and "hard" clumping. The soft is a bacterial '" soft clue" and the hard is the "welding", where Ca++ combines with CO3--.
macclellan
New member
If ETRC can get an indoor co2 meter, I'd love to run some tests w/w-out housplants w/w-out refugium, and w/w-out skimmer, now that I've got a pH probe and a data-logging controller. I'd love nothing more than to disprove my own hypothesis. 
Without further evidence, I'll stay silent on houseplants. Until then, as crappy as the air quality is in East TN, I'll keep them inside.
I will address the co2 issue in planted tanks, though (there is no more complex, dynamic, or controversial issue in freshwater planted):
Yes, IMHO all reef clubs should have one [in home co2 meter]. However, your original statement on metes implies that there is one for measuring CO2 in water and the is not. So, Now I know what you mean by CO2 meter.
I mentioned both, and there are both. In-home (air) co2 meters are reasonably priced (~$100). Dissolved co2 meters are uncommon since they are way out of the range of almost all hobbyists (thousands of dollars). I'm not sure why you keep trying to deny that they exist though. Most are designed for measuring carbonated beverages, but for example, this one is suitable for planted tanks.
I'm not saying it is not but it has no bearing on how much CO2 is in the tank, as some of that will degass off. So, why even say it? That is like measuring the pH of where you drip kalk and it is pH 10 or measuring the output pH of a reactor and it is 6.5 . None of those tell you what the tank pH is. Your remark has no bearing on the issue at hand and is misleading to a reader.
CO2 is much more variable in a co2-injected aquarium than I think occcurs to a reef tank's pH with a kalk drip, and varies much much more than most people think. What's the usual rate of kalkwasser drip? I thought it was quite low, off most of the time, dripping occasionally, etc. (just guessing, never used kalkwasser). In planted tanks, we are talking several BPS of CO2 constantly injected throughout the whole photoperiod. Also, flowrates are much lower in planted tanks than reefs, exacerbating the difference. I would think that CO2 in planted and PAR measurements would be a more accurate analogy than CO2 and kalk. Here's an interesting thread on the variability of CO2 levels in planted tanks if you're interested. It's actually amazing that fish can survive in planted tanks with such wide pH differences, hence my earlier question about co2-caused pH drop in marine aquaria.
Not EVERYBODY that runs a PFW have algae issues at 10-25.
Well, not EVERYBODY that shoots themselves in the face dies, but it's still not good advice.
With low light tanks, low levels of co2 are fine (i.e., no co2 injected). But in so-called 'high tech' tanks (high light/injected co2... what is typically meant by "planted tanks") you WILL get algae problems (specifically Black Brush alga and various hair/thread algae) at 10ppm co2 (taking the measurement in open water away from the co2 input, not down in the plant beds where it is much lower). Well, at least I have, and lots of others. Got algae? Increase co2 or decrease light. Also, it's not for no reason that co2 drop checkers (4dk solution with ph reagent in a glass ball underwater) are designed to turn green at 30ppm, show blue below that (too low co2). Most folks run co2 a bit 'hotter' so that the drop checker shows lime green. Have you successfully ran a high-light planted tank at 10ppm co2?
There are also quite a few PFW tank websties and forums that suggest 10-25. So, we can always pick and choose what website or forum to go to
Well, there are websites with all kinds of opinions, but PT.net and APC.com are the most respected planted-tank specific forums. Together, they are to planted tanks as RC is to reef tanks.
You have a pH range or swing of 8.0- 8.2 ? Well that is what many seek Refugium and skimmer do work well for many but it depends on how the individual wants to address the issue, how low that pH is and what its swing is.
I have two reef tanks, one with a refugium at 8 and one with just a skimmer at 8.2; sorry if what I said in the earlier post suggested otherwise.
Without further evidence, I'll stay silent on houseplants. Until then, as crappy as the air quality is in East TN, I'll keep them inside. I will address the co2 issue in planted tanks, though (there is no more complex, dynamic, or controversial issue in freshwater planted):
Yes, IMHO all reef clubs should have one [in home co2 meter]. However, your original statement on metes implies that there is one for measuring CO2 in water and the is not. So, Now I know what you mean by CO2 meter.
I mentioned both, and there are both. In-home (air) co2 meters are reasonably priced (~$100). Dissolved co2 meters are uncommon since they are way out of the range of almost all hobbyists (thousands of dollars). I'm not sure why you keep trying to deny that they exist though. Most are designed for measuring carbonated beverages, but for example, this one is suitable for planted tanks.
I'm not saying it is not but it has no bearing on how much CO2 is in the tank, as some of that will degass off. So, why even say it? That is like measuring the pH of where you drip kalk and it is pH 10 or measuring the output pH of a reactor and it is 6.5 . None of those tell you what the tank pH is. Your remark has no bearing on the issue at hand and is misleading to a reader.
CO2 is much more variable in a co2-injected aquarium than I think occcurs to a reef tank's pH with a kalk drip, and varies much much more than most people think. What's the usual rate of kalkwasser drip? I thought it was quite low, off most of the time, dripping occasionally, etc. (just guessing, never used kalkwasser). In planted tanks, we are talking several BPS of CO2 constantly injected throughout the whole photoperiod. Also, flowrates are much lower in planted tanks than reefs, exacerbating the difference. I would think that CO2 in planted and PAR measurements would be a more accurate analogy than CO2 and kalk. Here's an interesting thread on the variability of CO2 levels in planted tanks if you're interested. It's actually amazing that fish can survive in planted tanks with such wide pH differences, hence my earlier question about co2-caused pH drop in marine aquaria.
Not EVERYBODY that runs a PFW have algae issues at 10-25.
Well, not EVERYBODY that shoots themselves in the face dies, but it's still not good advice.
With low light tanks, low levels of co2 are fine (i.e., no co2 injected). But in so-called 'high tech' tanks (high light/injected co2... what is typically meant by "planted tanks") you WILL get algae problems (specifically Black Brush alga and various hair/thread algae) at 10ppm co2 (taking the measurement in open water away from the co2 input, not down in the plant beds where it is much lower). Well, at least I have, and lots of others. Got algae? Increase co2 or decrease light. Also, it's not for no reason that co2 drop checkers (4dk solution with ph reagent in a glass ball underwater) are designed to turn green at 30ppm, show blue below that (too low co2). Most folks run co2 a bit 'hotter' so that the drop checker shows lime green. Have you successfully ran a high-light planted tank at 10ppm co2?There are also quite a few PFW tank websties and forums that suggest 10-25. So, we can always pick and choose what website or forum to go to
Well, there are websites with all kinds of opinions, but PT.net and APC.com are the most respected planted-tank specific forums. Together, they are to planted tanks as RC is to reef tanks.
You have a pH range or swing of 8.0- 8.2 ? Well that is what many seek
Refugium and skimmer do work well for many but it depends on how the individual wants to address the issue, how low that pH is and what its swing is.I have two reef tanks, one with a refugium at 8 and one with just a skimmer at 8.2; sorry if what I said in the earlier post suggested otherwise.
:lol:<a href=showthread.php?s=&postid=15673542#post15673542 target=_blank>Originally posted</a> by macclellan
Well, not EVERYBODY that shoots themselves in the face dies, but it's still not good advice.
I'm up for buying a CO2 meter for the club if its around $100 or so... Anyone have a link to a decent one???
I'm not sure why you keep trying to deny that they exist though.
I know they exist it was a ploy to get you to look them up to see what one costs and how far they are outside a hobbyist price range You come across like many plant guys have one and they are common. They are also special ones for seawater, using a pCO2 probe and float around on buoys called RDA ( Remote Data Stations). I have brought these up before on RC and else where.
What's the usual rate of kalkwasser drip? I thought it was quite low, off most of the time, dripping occasionally, etc. (just guessing, never used kalkwasser).
Some drip at night only to remove excessive CO2. Some use 24/7 Kalk reactors, for Alk, pH and Ca++. Kalk is the ideal way to run a reef tank **IF one can use just kalk as a single means, as it adds nothing to the tank extra, like CA, or two part sup's, just Ca++ and Alk (carbonates).
I'll have to have a talk with Tom at MACNA
From Tom
Some interfering ions for pH/KH that are common:
Ammonium, PO4, borates, hydroxides, all things that are present in most planted tanks.
This method gets around that, gives accurate fast readings
It's more accurate than the pH/KH table assuming it is correct and all the Carbonate is Alkalinity and that the pH is only influenced by bicarbonate and CO2.
This is true but not if you understand the proper equations for it, it is not really any more accurate. All of the CO2 calculators give a good enough value for any planted tank. One can get around what Tom says by using an actual carbonate alkalinity test kit and not a total alk kit and using that for the calculator. It can be made even more accurate if you put in the temp and the TDS of the water. The meter works nice if one wants to do some research and move the probe around.
Well, not EVERYBODY that shoots themselves in the face dies, but it's still not good advice
Really, then Tom must be shooting himself His CO2 avg is ~20 ppm within the 10 -25 I gave Next to the source does not count ever.
5 cm away: 40-100ppm
30-40 cm away: 20-30ppm
Within the plant beds: 8-12 ppm
Now for a 20 Gallon tank with 250 Gallons per hour flow:
5 cm from CO2 source: 35ppm
15 cm: 30ppm
30 cm: 22ppm
50 cm 17ppm
Within plant beds(dense): 6-12ppm
Have you successfully ran a high-light planted tank at 10ppm co2?
No but I have friends that run them in the 20's and I said 10-25 so the is within what I gave. An not all PT are high lit are they
(high light/injected co2... what is typically meant by "planted tanks")
Not in my world. A PT is a FW tank with lots of plants and not all are high lit or use CO2 injection. PT have been around for 40 years. CO2 injection was brought to us more or less by Dupla back in the 80's. And there were called PT before there was any CO2 injection You need to quite defining things as only you see them
but it's still not good advice
You are rather poor on advice from what I've seen
I would think that CO2 in planted and PAR measurements would be a more accurate analogy than CO2 and kalk
You need to explain that as it makes no sense at all as it stands. A PAR tells you nothing about water chemistry, it is just how much light is there. Yes, you may see trend if you increase the PAR in a PT and the CO2 drops an you need more. However, that is not always the case, especially in a reef tank. A PAR value and CO2 does not tell you what the Calcium, Alk or what the pH is. And a PAR and CO2 value in a PT does not tell you the pH or Alk is either. Proper PAR and CO2 for x tank does not = Success.
I have two reef tanks, one with a refugium at 8 and one with just a skimmer at 8.2; sorry if what I said in the earlier post suggested otherwise
Nope that is fine those are good levels 7.6 - 8.0 IS NOT
I know they exist it was a ploy to get you to look them up to see what one costs and how far they are outside a hobbyist price range
You come across like many plant guys have one and they are common. They are also special ones for seawater, using a pCO2 probe and float around on buoys called RDA ( Remote Data Stations). I have brought these up before on RC and else where.What's the usual rate of kalkwasser drip? I thought it was quite low, off most of the time, dripping occasionally, etc. (just guessing, never used kalkwasser).
Some drip at night only to remove excessive CO2. Some use 24/7 Kalk reactors, for Alk, pH and Ca++. Kalk is the ideal way to run a reef tank **IF one can use just kalk as a single means, as it adds nothing to the tank extra, like CA, or two part sup's, just Ca++ and Alk (carbonates).
I'll have to have a talk with Tom at MACNA
From Tom
Some interfering ions for pH/KH that are common:
Ammonium, PO4, borates, hydroxides, all things that are present in most planted tanks.
This method gets around that, gives accurate fast readings
It's more accurate than the pH/KH table assuming it is correct and all the Carbonate is Alkalinity and that the pH is only influenced by bicarbonate and CO2.
This is true but not if you understand the proper equations for it, it is not really any more accurate. All of the CO2 calculators give a good enough value for any planted tank. One can get around what Tom says by using an actual carbonate alkalinity test kit and not a total alk kit and using that for the calculator. It can be made even more accurate if you put in the temp and the TDS of the water. The meter works nice if one wants to do some research and move the probe around.
Well, not EVERYBODY that shoots themselves in the face dies, but it's still not good advice
Really, then Tom must be shooting himself
His CO2 avg is ~20 ppm within the 10 -25 I gave Next to the source does not count ever.5 cm away: 40-100ppm
30-40 cm away: 20-30ppm
Within the plant beds: 8-12 ppm
Now for a 20 Gallon tank with 250 Gallons per hour flow:
5 cm from CO2 source: 35ppm
15 cm: 30ppm
30 cm: 22ppm
50 cm 17ppm
Within plant beds(dense): 6-12ppm
Have you successfully ran a high-light planted tank at 10ppm co2?
No but I have friends that run them in the 20's and I said 10-25 so the is within what I gave. An not all PT are high lit are they
(high light/injected co2... what is typically meant by "planted tanks")
Not in my world. A PT is a FW tank with lots of plants and not all are high lit or use CO2 injection. PT have been around for 40 years. CO2 injection was brought to us more or less by Dupla back in the 80's. And there were called PT before there was any CO2 injection
You need to quite defining things as only you see them but it's still not good advice
You are rather poor on advice from what I've seen
I would think that CO2 in planted and PAR measurements would be a more accurate analogy than CO2 and kalk
You need to explain that as it makes no sense at all as it stands. A PAR tells you nothing about water chemistry, it is just how much light is there. Yes, you may see trend if you increase the PAR in a PT and the CO2 drops an you need more. However, that is not always the case, especially in a reef tank. A PAR value and CO2 does not tell you what the Calcium, Alk or what the pH is. And a PAR and CO2 value in a PT does not tell you the pH or Alk is either. Proper PAR and CO2 for x tank does not = Success.
I have two reef tanks, one with a refugium at 8 and one with just a skimmer at 8.2; sorry if what I said in the earlier post suggested otherwise
Nope that is fine those are good levels 7.6 - 8.0 IS NOT
macclellan
New member
I'd agree that 20-30ppm is a good average in a tank, but that would be 30+ in open water, where test water is drawn from, dropcheckers placed, pH probes, etc. The plant beds are a small part of the water volume (say, 30% in most cases). I don't know of anyone who takes multiple samples, accounts for water volume per sample, averages, etc. In a tank that needs injected co2 (i.e. a high light tank), 10ppm is a disastrously low average level. That's all I've been trying to say. Low light tanks are different, and don't need added co2.
We've been talking about co2 levels in planted tanks from 10-30ppm, and attaining these levels requires co2 injection. I'm of course aware of the history of the hobby and non-co2 injected tanks (I have two myself!), but that's not what we're talking about. If that's what we're talking about, then we could say 4-30ppm are acceptable, which is incredibly misleading and a recipe for disaster for anyone controlling co2, especially considering that fluctuating co2 (fiddling with needle-valves, raising spraybar to outgass, etc.) cause algae just as low co2 does.
You need to explain that as it makes no sense at all as it stands. A PAR tells you nothing about water chemistry, it is just how much light is there.
I just meant that co2 levels vary widely in a tank (threefold plus differences throughout the water column), like PAR levels (and not pH levels in reef tanks), so it is a more apt analogy.
Let's stop there, since you don't actually have any experience with planted tanks; you just seem to like arguing as much as I do.
We've been talking about co2 levels in planted tanks from 10-30ppm, and attaining these levels requires co2 injection. I'm of course aware of the history of the hobby and non-co2 injected tanks (I have two myself!), but that's not what we're talking about. If that's what we're talking about, then we could say 4-30ppm are acceptable, which is incredibly misleading and a recipe for disaster for anyone controlling co2, especially considering that fluctuating co2 (fiddling with needle-valves, raising spraybar to outgass, etc.) cause algae just as low co2 does.
You need to explain that as it makes no sense at all as it stands. A PAR tells you nothing about water chemistry, it is just how much light is there.
I just meant that co2 levels vary widely in a tank (threefold plus differences throughout the water column), like PAR levels (and not pH levels in reef tanks), so it is a more apt analogy.
Let's stop there, since you don't actually have any experience with planted tanks; you just seem to like arguing as much as I do.
