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Swamp Creek - 2 years on updated June 2012
- Thread starter tyrophagus
- Start date
Re: Swamp Creek
I feel a bit ashamed that I've missed this journal.
It's a fascinating read from start to present and I've learnt loads, especially about the LEDs. Thanks very much for taking the time and effort to publish your results!
Are you using tap water? Is it very hard by any chance?
I feel a bit ashamed that I've missed this journal.
It's a fascinating read from start to present and I've learnt loads, especially about the LEDs. Thanks very much for taking the time and effort to publish your results!
Are you using tap water? Is it very hard by any chance?
tyrophagus
Member
Re: Swamp Creek
George I'm using tap water and it's hard as nails. Is there something I should know about that? I'm not keen on making RO water - used to do it and it put me off the hobby to be honest. Much prefer a hose straight into the tank.
George I'm using tap water and it's hard as nails. Is there something I should know about that? I'm not keen on making RO water - used to do it and it put me off the hobby to be honest. Much prefer a hose straight into the tank.
Re: Swamp Creek
I understand that it's tougher to grow plants in mega hard water, usually because more CO2 injection is necessary to get appropriate CO2 levels. I don't understand the science behind it though, I'm afraid.tyrophagus said:
Re: Swamp Creek
Hi all,
cheers Darrel
Hi all,
This is because of the carbon dioxide >< carbonate >< bicarbonate equation. At high levels of bicarbonate (HCO3) the plants are CO2 limited, and must use bicarb. as their dissolved inorganic carbon (DIC) source. A few plants from hard waters can do this fairly well, but most have a limited ability to utilise carbonates. I've pinched the pukka explanation from one of Clive's posts:
Another issue is the conversion of orthophosphates (PO4) to relatively insoluble calcium phosphate compounds in hard, carbonate rich water.
cheers Darrel
Re: Swamp Creek
Does this mean that some plants may have a tough time growing in very hard water?
Hi Darreldw1305 said:
Does this mean that some plants may have a tough time growing in very hard water?
Re: Swamp Creek
George,
While some plants may have a preference for alkalinity or even for TDS, very few cannot be grown in high alkalinity/GH. The carbonate/bicarbonate-carbonic acid equilibrium i.e. the tables showing KH/PH/CO2 relationship is only valid for a small amount of the CO2 dissolved in water.
For our purpose there is little or no difference in solubility of CO2 in hard or soft water. All gases that dissolve in water do so fundamentally as a function of their partial pressure and temperature of the water. It really isn't any tougher to dissolve CO2 in hard water.
CO2 is exceptional and varies from ideal behavior because it reacts with the water, as opposed to gases such as Oxygen or Nitrogen, and this reaction modifies the apparent solubility, but not enough for us to worry about.
When CO2 dissolves in water, somewhere between 0.2% and 1.0% of the dissolved CO2 reacts with the water to form Carbonic acid (H2CO3). This is part of the equation Darrel refers to:
CO2 + H2O <> H2CO3
Carbonic acid is a weak unstable acid and reacts with the water further to disassociate, first into bicarbonate (HCO3-)...
H2CO3 + H2O <> H3O+ + HCO3-
and then to carbonate (CO3--)
HCO3- + H2O <> H3O+ + CO3--
Do you see the double headed arrow (<>)? That means the reaction can go either way depending on how much of each product is available. The phenomenon responsible for driving the reactions from left to right (->), or from right to left (<-), is the quantity, distribution, or behavior of the charged particles on either side of the double headed arrow.
Can you see where the carbonate has a double negative electric charge (CO3--) and the bicarbonate has a single electric charge (HCO3-)? Well, water that is hard has a lot of positively charged particles such as Magnesium (Mg++) and Calcium (Ca++). The double positive Mg++ can combine with the double negative CO3-- and form MgCO3 which is chalk and which can precipitate out of solution. The same for the Calcium, which can form CaCO3. These reactions tend to remove CO3-- from the equation effectively acting as a hoover to unbalance the equation and to pull the reactions to the right (->).
But removal of carbonate/bicarbonate also makes the water more acidic and therefore a more acidic water will dissolve the precipitates like chalk which sends the carbonates back into solution driving the equation to the left (<-) and pushing the CO2 back into solution.
This is why the overall effect is of hard water is essentially transparent. It just like being on a Ferris wheel. And of course, this all applies only to a maximum of 1% of the CO2 at room temperature. The percentage falls to about 0.2% as the temperature increases to our tropical (but so does the solubility of the gas). The other 99% of the gas stays in solution as CO2.
Because of these reactions the carbonate/bicarbonate content of the water affects the rate at which CO2 moves into and out of solution, but it does not affect the concentration at equilibrium. People often refer to the charts which show the quantitative relationship of the various DIC species as a function of pH. They forget that when the natural pH of a given water sample is high in pH it also is typically high in carbonates/bicarbonates so that the ratio of carbonates to CO2 is overwhelmingly high but the amount of dissolved CO2 is the same as water low in KH.
Cheers,
George,
While some plants may have a preference for alkalinity or even for TDS, very few cannot be grown in high alkalinity/GH. The carbonate/bicarbonate-carbonic acid equilibrium i.e. the tables showing KH/PH/CO2 relationship is only valid for a small amount of the CO2 dissolved in water.
For our purpose there is little or no difference in solubility of CO2 in hard or soft water. All gases that dissolve in water do so fundamentally as a function of their partial pressure and temperature of the water. It really isn't any tougher to dissolve CO2 in hard water.
CO2 is exceptional and varies from ideal behavior because it reacts with the water, as opposed to gases such as Oxygen or Nitrogen, and this reaction modifies the apparent solubility, but not enough for us to worry about.
When CO2 dissolves in water, somewhere between 0.2% and 1.0% of the dissolved CO2 reacts with the water to form Carbonic acid (H2CO3). This is part of the equation Darrel refers to:
CO2 + H2O <> H2CO3
Carbonic acid is a weak unstable acid and reacts with the water further to disassociate, first into bicarbonate (HCO3-)...
H2CO3 + H2O <> H3O+ + HCO3-
and then to carbonate (CO3--)
HCO3- + H2O <> H3O+ + CO3--
Do you see the double headed arrow (<>)? That means the reaction can go either way depending on how much of each product is available. The phenomenon responsible for driving the reactions from left to right (->), or from right to left (<-), is the quantity, distribution, or behavior of the charged particles on either side of the double headed arrow.
Can you see where the carbonate has a double negative electric charge (CO3--) and the bicarbonate has a single electric charge (HCO3-)? Well, water that is hard has a lot of positively charged particles such as Magnesium (Mg++) and Calcium (Ca++). The double positive Mg++ can combine with the double negative CO3-- and form MgCO3 which is chalk and which can precipitate out of solution. The same for the Calcium, which can form CaCO3. These reactions tend to remove CO3-- from the equation effectively acting as a hoover to unbalance the equation and to pull the reactions to the right (->).
But removal of carbonate/bicarbonate also makes the water more acidic and therefore a more acidic water will dissolve the precipitates like chalk which sends the carbonates back into solution driving the equation to the left (<-) and pushing the CO2 back into solution.
This is why the overall effect is of hard water is essentially transparent. It just like being on a Ferris wheel. And of course, this all applies only to a maximum of 1% of the CO2 at room temperature. The percentage falls to about 0.2% as the temperature increases to our tropical (but so does the solubility of the gas). The other 99% of the gas stays in solution as CO2.
Because of these reactions the carbonate/bicarbonate content of the water affects the rate at which CO2 moves into and out of solution, but it does not affect the concentration at equilibrium. People often refer to the charts which show the quantitative relationship of the various DIC species as a function of pH. They forget that when the natural pH of a given water sample is high in pH it also is typically high in carbonates/bicarbonates so that the ratio of carbonates to CO2 is overwhelmingly high but the amount of dissolved CO2 is the same as water low in KH.
Cheers,
Re: Swamp Creek
Hi all,
Yes I think Clive is right, I wasn't really thinking about adding CO2, so in that case the CO2 will be available in a way that it wouldn't be in carbonate rich water without the continual CO2 addition. This then becomes the relevant bit:
I think that a similar equilibrium would apply to some of the calcium phosphate complexes, they would definitely be more soluble in a weak acid solvent, but I'm not sure which compounds would form in the tank water, and some are more soluble than others. The chemistry for this is well beyond me because as well as the "acid–base reaction", factors like "solubility in the presence of a common ion" and "selective precipitation" will come into play.
cheers Darrel
Hi all,
Yes I think Clive is right, I wasn't really thinking about adding CO2, so in that case the CO2 will be available in a way that it wouldn't be in carbonate rich water without the continual CO2 addition. This then becomes the relevant bit:
This means that plants that you would struggle to grow in carbonate rich water (because of their inability to utilise bicarbonates) should grow in CO2 enriched situations.
I think that a similar equilibrium would apply to some of the calcium phosphate complexes, they would definitely be more soluble in a weak acid solvent, but I'm not sure which compounds would form in the tank water, and some are more soluble than others. The chemistry for this is well beyond me because as well as the "acid–base reaction", factors like "solubility in the presence of a common ion" and "selective precipitation" will come into play.
cheers Darrel
Re: Swamp Creek
Thanks, Clive and Darrel.
So to summarise, for those that don't understand all the science, as long as you can supply sufficient CO2, the hardness of the water should not make much difference in terms of the ability to successfully grow plants.
Thanks, Clive and Darrel.
So to summarise, for those that don't understand all the science, as long as you can supply sufficient CO2, the hardness of the water should not make much difference in terms of the ability to successfully grow plants.
Re: Swamp Creek
Yes mate, I do apologize for the geek speak, but it's not easy to explain in non-scientific terms. The solubility of any gas is fundamentally a function of the partial pressure of that gas and the temperature of the water. We won't see any differences for the range of water values we use. So the only people who will see a real difference in ability to dissolve CO2 will be those people living in high altitude cities such as Denver, La Paz, Lhasa, Quito and cities at similar altitudes where the atmospheric pressures are significantly lower. CO2 is about 26% less soluble at 30 degrees C. than it is at 20 degrees C. and so these parameters have orders of magnitude more impact than does the hardness of the water, therefore water hardness should never be used as an explanation for poor performance. Tyrophagus himself saw a 100% increase in CO2 efficiency (10 bps to 5 bps) as a result of reconfiguring his flow (I assume he was using the same water), so right off the bat this demonstrates that the issues in the tank have little to do with water hardness.
Here is my standard shot showing a variety of plants in "hard as nails" water. This water had 3X the conductivity of Lake Malawi, double the GH of Lake Tanganyika and a 50% higher alkalinity than either, yet I had no problems whatsoever with CO2:
Cheers,
Yes mate, I do apologize for the geek speak, but it's not easy to explain in non-scientific terms. The solubility of any gas is fundamentally a function of the partial pressure of that gas and the temperature of the water. We won't see any differences for the range of water values we use. So the only people who will see a real difference in ability to dissolve CO2 will be those people living in high altitude cities such as Denver, La Paz, Lhasa, Quito and cities at similar altitudes where the atmospheric pressures are significantly lower. CO2 is about 26% less soluble at 30 degrees C. than it is at 20 degrees C. and so these parameters have orders of magnitude more impact than does the hardness of the water, therefore water hardness should never be used as an explanation for poor performance. Tyrophagus himself saw a 100% increase in CO2 efficiency (10 bps to 5 bps) as a result of reconfiguring his flow (I assume he was using the same water), so right off the bat this demonstrates that the issues in the tank have little to do with water hardness.
Here is my standard shot showing a variety of plants in "hard as nails" water. This water had 3X the conductivity of Lake Malawi, double the GH of Lake Tanganyika and a 50% higher alkalinity than either, yet I had no problems whatsoever with CO2:
Cheers,
tyrophagus
Member
Re: Swamp Creek
Its an interesting read. I don't think I appreciated how complex the science could be. So I should be able to grow almost anything in my water as long as I follow basic principals of high optimised flow, EI or equivalent, Light at an appropriate PAR and as much CO2 as my fish can live with.
So that leaves me with a question. Why do my crypts keep melting? I can lose an entire crypt over a few months. When I say lose I mean that the leaves melt, one by one and the plant grows new ones which also melt until the root is to weak to sustain new growth and the crypt dies. The leaves that die are young and old. I have 6 varieties and they are all affected.
Ok so it's not a disease. It's a response to changes in the environment, the plant does not like change especially fluctuation in CO2.
I've thought long and hard about it and tried a few things.
1. I don't move them around.
2. I take care not to damage leaves at water change.
3. I've improved my CO2 and flow - I thought this made a difference BUT its happened again.
4. I'm waiting on an UP Atomiser so perhaps my CO2 can be improved even more.
5. I prune back damaged leaves.
6. I do at least 50 - 70% water changes once a week.
If I have noticed one trend over the months it's that the melts occur straight after water change days. I thought it might be the change in co2 on water change day but now I wonder if it's the sudden change in the overall hardness of my tank water before the CO2 has a chance to "soften" it by making some calcium and magnesium insoluble.
Thing is that Clive you manage to grow plants in really hard water and your water changes were huge if I recall so I'm not convinced.
I plan to switch to a 25% water change twice a week and see what happens. Do you think my latest theory makes sense?
--------------------- water info ----------------------
My tap water (conductivity is accurate, the KH/GH were measure with an expired kit)
Conductivity 760us
KH 230
GH 240
Thames Water analysis for local area
ph 7.2
conductivity 598 us
TH (cac03) 344
Its an interesting read. I don't think I appreciated how complex the science could be. So I should be able to grow almost anything in my water as long as I follow basic principals of high optimised flow, EI or equivalent, Light at an appropriate PAR and as much CO2 as my fish can live with.
So that leaves me with a question. Why do my crypts keep melting? I can lose an entire crypt over a few months. When I say lose I mean that the leaves melt, one by one and the plant grows new ones which also melt until the root is to weak to sustain new growth and the crypt dies. The leaves that die are young and old. I have 6 varieties and they are all affected.
Ok so it's not a disease. It's a response to changes in the environment, the plant does not like change especially fluctuation in CO2.
I've thought long and hard about it and tried a few things.
1. I don't move them around.
2. I take care not to damage leaves at water change.
3. I've improved my CO2 and flow - I thought this made a difference BUT its happened again.
4. I'm waiting on an UP Atomiser so perhaps my CO2 can be improved even more.
5. I prune back damaged leaves.
6. I do at least 50 - 70% water changes once a week.
If I have noticed one trend over the months it's that the melts occur straight after water change days. I thought it might be the change in co2 on water change day but now I wonder if it's the sudden change in the overall hardness of my tank water before the CO2 has a chance to "soften" it by making some calcium and magnesium insoluble.
Thing is that Clive you manage to grow plants in really hard water and your water changes were huge if I recall so I'm not convinced.
I plan to switch to a 25% water change twice a week and see what happens. Do you think my latest theory makes sense?
--------------------- water info ----------------------
My tap water (conductivity is accurate, the KH/GH were measure with an expired kit)
Conductivity 760us
KH 230
GH 240
Thames Water analysis for local area
ph 7.2
conductivity 598 us
TH (cac03) 344
Re: Swamp Creek
Yes, there's nothing wrong with that water except that the Sodium looks kind of high and it probably taste's nasty. Sodium is the one ion that frightens me and it can weaken the plants so that they are susceptible to other issues.
My water changes are 70% at a minimum and are sometimes somewhere on the order of 90%, so these have nothing to do with crypt melt. That is strictly a CO2 issue. I damage my crypts all the time. Sometimes I pour boiling water over them. I move them around quite regularly. They just don't melt.
I don't recall exactly now whether you supplement with Excel, but this is a great tool to use when troubleshooting CO2 issues. If you see increased performance or better durability when supplementing, then this confirms that you have a CO2/flow/light issue.
Cheers,
Yes, there's nothing wrong with that water except that the Sodium looks kind of high and it probably taste's nasty. Sodium is the one ion that frightens me and it can weaken the plants so that they are susceptible to other issues.
My water changes are 70% at a minimum and are sometimes somewhere on the order of 90%, so these have nothing to do with crypt melt. That is strictly a CO2 issue. I damage my crypts all the time. Sometimes I pour boiling water over them. I move them around quite regularly. They just don't melt.
I don't recall exactly now whether you supplement with Excel, but this is a great tool to use when troubleshooting CO2 issues. If you see increased performance or better durability when supplementing, then this confirms that you have a CO2/flow/light issue.
Cheers,
tyrophagus
Member
Re: Swamp Creek
I use Excel daily, about 10ml in 200l. I'll work on my CO2. Cheers.
I use Excel daily, about 10ml in 200l. I'll work on my CO2. Cheers.
.
Re: Swamp Creek
I was wondering when someone would ask that. It's not because I love to torture crypts! 
With a sodium based water softener system I was unwilling to use the warm water for water changes. I was forced to use the untreated water from the outside tap for my water changes. This made things really difficult in the winter so I would boil huge quantities of water to control the temperature. As cold water from the hose was entering the tank I would carefully pour the hot water into the tank. I used my largest crypt as the target for the hot water input just after the water level rose above that plant. Not the most elegant solution, but that's how I know how tough crypts are. Given enough CO2/nutrients they are bulletproof...
Cheers,
I was wondering when someone would ask that. It's not because I love to torture crypts! With a sodium based water softener system I was unwilling to use the warm water for water changes. I was forced to use the untreated water from the outside tap for my water changes. This made things really difficult in the winter so I would boil huge quantities of water to control the temperature. As cold water from the hose was entering the tank I would carefully pour the hot water into the tank. I used my largest crypt as the target for the hot water input just after the water level rose above that plant. Not the most elegant solution, but that's how I know how tough crypts are. Given enough CO2/nutrients they are bulletproof...Cheers,
tyrophagus
Member
Re: Swamp Creek
UP Aqua atomiser installed. I've seen a big improvement in flow. I think I'm imagining things but the bba algae on some leaves seems to be turning into "pepper corns" if you know what I mean. It's only been about 4 days.
UP Aqua atomiser installed. I've seen a big improvement in flow. I think I'm imagining things but the bba algae on some leaves seems to be turning into "pepper corns" if you know what I mean. It's only been about 4 days.
tyrophagus
Member
Re: Swamp Creek
A video. just have to get that hair grass growing
A video. just have to get that hair grass growing
Re: Swamp Creek
Great little video of a lovely 'scape!
I like the high amount of surface movement, giving you nice glitter lines.
Thanks for sharing.
Great little video of a lovely 'scape!
I like the high amount of surface movement, giving you nice glitter lines.
Thanks for sharing.
