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: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.
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: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.
Another issue is the conversion of orthophosphates (PO4) to relatively insoluble calcium phosphate compounds in hard, carbonate rich water.Bicarbonate (HCO3) is also considered DIC, so waters that might have a high bicarbonate content may evolve plants which have a strategy to convert bicarbonate to CO2. This is yet another incredible mechanism whereby the plant send Hydrogen ions (H+) out from the abaxial surface (the bottom of the leaf). H+ is basically acid and this converts the bicarbonate to CO2. The plant then uptakes this CO2. This mechanis is called "proton pumping" because a hydrogen ion has no electrons but simply a proton in the nucleus (or the nucleus may have a proton and an uncharged neutron.) The bicarbonate strategy is employed during times of very low CO2 levels and only about half of our plants have this capability.....
Hi Darreldw1305 said: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: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.
Another issue is the conversion of orthophosphates (PO4) to relatively insoluble calcium phosphate compounds in hard, carbonate rich water.Bicarbonate (HCO3) is also considered DIC, so waters that might have a high bicarbonate content may evolve plants which have a strategy to convert bicarbonate to CO2. This is yet another incredible mechanism whereby the plant send Hydrogen ions (H+) out from the abaxial surface (the bottom of the leaf). H+ is basically acid and this converts the bicarbonate to CO2. The plant then uptakes this CO2. This mechanis is called "proton pumping" because a hydrogen ion has no electrons but simply a proton in the nucleus (or the nucleus may have a proton and an uncharged neutron.) The bicarbonate strategy is employed during times of very low CO2 levels and only about half of our plants have this capability.....
cheers Darrel
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.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.
ceg4048 said:I damage my crypts all the time. Sometimes I pour boiling water over them. Cheers,