We have fairly high phosphates in our tap water here in the South East, I have used a nitrate remover which works quite well but now do 50/50 RO/tap.Your stressing me about my water now mate. Any chance of you testing my water ehen we meet up?. I could always arrange a sample
Cheers
thegeeman
does TDS monitor help?
- Thread starter Irene0100
- Start date
Hi all,
Phosphates are a bit of funny one, as they are one of the essential macro nutrients for plant growth (They are the P from NPK), but plants only require them in relatively small amounts when compared to either N(itrogen) or K(Potassium). There availability is all dependent upon pH, with high pH (above 7) causing the phosphorus to precipitate out as relatively insoluble calcium phosphates. Phosphates also have a complex interaction with materials with a high anion exchange capacity (clay minerals, including calcined ones (fluorite, hydroleca, akadama, vermiculite etc).
They are a real problem in the water column of lakes and rivers in S. Britain, as they occur at high levels causing the familiar algal blooms (assuming other macro/micro nutrients are also present) of both "blanket weed" & "green water". I'd only deliberately add them to the tank if I had a real reason to suspect that P was in deficit, and I'd add them to the substrate (I use small balls of clay with a few granules of "growmore" (NPK 7-7-7) in the middle, rolled into the ball) allow them to dry and push them into the root ball of Amazon Swords etc. Potassium nitrate would be fertilizer of choice to use in the water column (to add N and K).
cheers Darrel
Phosphates are a bit of funny one, as they are one of the essential macro nutrients for plant growth (They are the P from NPK), but plants only require them in relatively small amounts when compared to either N(itrogen) or K(Potassium). There availability is all dependent upon pH, with high pH (above 7) causing the phosphorus to precipitate out as relatively insoluble calcium phosphates. Phosphates also have a complex interaction with materials with a high anion exchange capacity (clay minerals, including calcined ones (fluorite, hydroleca, akadama, vermiculite etc).
They are a real problem in the water column of lakes and rivers in S. Britain, as they occur at high levels causing the familiar algal blooms (assuming other macro/micro nutrients are also present) of both "blanket weed" & "green water". I'd only deliberately add them to the tank if I had a real reason to suspect that P was in deficit, and I'd add them to the substrate (I use small balls of clay with a few granules of "growmore" (NPK 7-7-7) in the middle, rolled into the ball) allow them to dry and push them into the root ball of Amazon Swords etc. Potassium nitrate would be fertilizer of choice to use in the water column (to add N and K).
cheers Darrel
My tap water also has a high phosphate reading, the darkest blue on the chart when i checked it.
But i think it helps buffer my very soft water in my tanks, the water authouritys must use it to buffer the tap water for the pipes, so that it dosn't corrode the pipes.
Is high phosphates detrimental to fish over time ?
But i think it helps buffer my very soft water in my tanks, the water authouritys must use it to buffer the tap water for the pipes, so that it dosn't corrode the pipes.
Is high phosphates detrimental to fish over time ?
Hi all,
Andrew, the water companies do add phosphate to the water, details (from earlier in this thread.
"..... the water company have added ortho-phosphate ("plumbosolvency") and an alkaline compound to your naturally soft and probably originally very good quality water, this is to stop it leaching lead (Pb) from old pipes, and to comply with much tighter guidelines on lead content in drinking water...."
I can't find much for the toxicity of phosphates on their own, as they are nearly always associated with high nitrates in the environment (Look up Eutrophication on Wikipedia <http://en.wikipedia.org/wiki/Eutrophication>).
Phosphorus is normally the limiting nutrient for plant/algae growth in ponds, streams etc which is why it "causes" algal blooms (the algal bloom requires all the other plant macro and micro nutrients to be present already).
I found this paper suggesting it may effect egg development at high levels (PM me if you want a copy)
Catarina I.M. Martins, Marco G. Pistrina, Stephan S.W. Endea, Ep H. Edinga and Johan A.J. Verretha (2009), "The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio".
Aquaculture, 291:1 pp. 65-73
".....Phosphate levels also differed significantly between RAS (high-accumulation water: 19.45 ± 0.89 mg/L; low-accumulation water: 0.51 ± 0.01 mg/L). Toor et al., 1983 H.S. Toor, H.S. Sehgal and C.S. Brar, Water-soluble phosphates: observed effects on embryonic development, hatching time, and survival of common carp, Prog. Fish-Cult. 45 (1983), pp. 134–135. Full Text via CrossRefToor et al. (1983) showed that levels of > 0.12 mg/L resulted in decreased hatching and increased incidence of larval deformities in carp. These results partly corroborate the results found in this study as a decreased hatching but not an increased incidence of deformities was observed in the incubation unit using water from the high-accumulation water as compared with the low-accumulation water....."
cheers Darrel
Andrew, the water companies do add phosphate to the water, details (from earlier in this thread.
"..... the water company have added ortho-phosphate ("plumbosolvency") and an alkaline compound to your naturally soft and probably originally very good quality water, this is to stop it leaching lead (Pb) from old pipes, and to comply with much tighter guidelines on lead content in drinking water...."
I can't find much for the toxicity of phosphates on their own, as they are nearly always associated with high nitrates in the environment (Look up Eutrophication on Wikipedia <http://en.wikipedia.org/wiki/Eutrophication>).
Phosphorus is normally the limiting nutrient for plant/algae growth in ponds, streams etc which is why it "causes" algal blooms (the algal bloom requires all the other plant macro and micro nutrients to be present already).
I found this paper suggesting it may effect egg development at high levels (PM me if you want a copy)
Catarina I.M. Martins, Marco G. Pistrina, Stephan S.W. Endea, Ep H. Edinga and Johan A.J. Verretha (2009), "The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio".
Aquaculture, 291:1 pp. 65-73
".....Phosphate levels also differed significantly between RAS (high-accumulation water: 19.45 ± 0.89 mg/L; low-accumulation water: 0.51 ± 0.01 mg/L). Toor et al., 1983 H.S. Toor, H.S. Sehgal and C.S. Brar, Water-soluble phosphates: observed effects on embryonic development, hatching time, and survival of common carp, Prog. Fish-Cult. 45 (1983), pp. 134–135. Full Text via CrossRefToor et al. (1983) showed that levels of > 0.12 mg/L resulted in decreased hatching and increased incidence of larval deformities in carp. These results partly corroborate the results found in this study as a decreased hatching but not an increased incidence of deformities was observed in the incubation unit using water from the high-accumulation water as compared with the low-accumulation water....."
cheers Darrel
thanks for that, I think this really becomes important when trying to breed stubborn fish! for general upkeep the tds and various tapwater chemicals are less critical and if you have poor tap water then also try and use some rain water if not into RO.
as good water = healthy fish
Also i noticed tds is often measures in different units, not just ppm, so you need to know what you are measuring it in too.
as good water = healthy fish
Also i noticed tds is often measures in different units, not just ppm, so you need to know what you are measuring it in too.
Units for measuring hardness - includes some chemistry
Hi all,
Irene wrote: "Also i noticed tds is often measures in different units, not just ppm, so you need to know what you are measuring it in too."
I agree it is a bit of a nightmare trying to get all the units sorted out. I'll have a go, and treat TDS and hardness as the same (they aren't exactly, but I'll explain why as I go a long).
TDS is total dissolved solids and hardness is a measure of dissolved multivalent minerals (Ca2+, Mg2+) in the water (multivalent just means there is a number in front of the +, e.g. Ca2+).
There are 2 types of hardness "temporary" where boiling will remove them - carbonates, usually calcium or magnesium, and "permanent" which can't be removed by boiling - sulph(f)ates, chlorides e.g. magnesium sulphate ("Epsom salts").
In the UK hardness is usually a measure of the calcium carbonate (the lime(stone), chalk or scale) content. The equilibrium reaction is:
CaCO3(solid) + H2CO3(aq. in solution) ⇋ Ca2+(aq) + 2HCO3-(aq) (exactly same for Mg2+ as well, so both Ca and Mg are usually added together and expressed just as calcium)
As you heat the water CO2 becomes less soluble (it's not in the equation as CO2, but bicarbonate is - 2 x HCO3-) which moves the equation from right to left (less CO2 means less bicarbonate ions HCO3- to balance the Ca2+ ions), Ca2+ can't remain in solution and are precipitated out as the "scale" (CaCO3) in your kettle, immersion heater etc.
Ion exchange resins (water softener) can remove both types of hardness by exchanging sodium (Na+) or potassium (K+) for the calcium and magnesium (but you would still have high conductivity and TDS).
As a further problem most hardness tests actually test the conductivity (and therefore the TDS - amount of "salts" - as ions, for sodium chloride Na+ Cl-) this can be slightly misleading as monovalent ions (Na+), don't contribute to the hardness, but do contribute to the conductivity (and TDS).
But here goes - a few equivalents first:
Parts per million (ppm) is the same as milligrams per litre (1000 cm3 in a litre, which for water weighs 1000g (a kilogram), 1000 milligrams in 1cm3 which weighs 1 gram).
Parts per billion (ppb) is micrograms per litre (1000 micrograms to the milligram).
mmol/L (millimoles per litre)
One millimole of calcium (either Ca2+ or CaCO3) per litre of water corresponds to a hardness of 100 ppm or 5.61 dGH, since the molar mass of calcium carbonate is 100g/mol (Ca has a RAM of 40, C = 12 and O = 16, CaCO3 = 40 + 12 + 48(16 x 3) = 100)
100g in 1 litre is a molar solution of calcium carbonate (40% Ca), and 0.1g per litre a millimolar solution.
General degrees of hardness is the same as German degrees (dGH).
1 dGH is "One degree German" and defined as 10 milligrams of calcium oxide (CaO) per litre of water. This is equivalent to 17.85 milligrams of calcium carbonate per litre of water, or 17.85 ppm. (look up American, Clark, French degrees etc. on Wikipedia for a conversion).
As an example my tap water (Corsham, Wilts - SN13 9AR) is (go to your water company in the UK and you can get average water figures for your postcode).
Calcium (milligrams per litre) 119 (298 x 40% = 119)
Calcium carbonate (milligrams per litre) 298
Degrees German (ºdH) 16.7 (16.7 x 17.85 = 298)
Degrees French (ºf) 30
Degrees Clark 21
Sodium (milligrams per litre) 22
Conductivity 615 micro S(iemens)
Descriptions of hardness correspond roughly with these ranges of mineral (Ca, Mg) concentrations: (pinched straight from Wikipedia)
* Very soft: 0-70 ppm, 0-4 dGH
* Soft: 70-140 ppm, 4-8 dGH
* Slightly hard: 140-210 ppm, 8-12 dGH
* Moderately hard: 210-320 ppm, 12-18 dGH
* Hard: 320-530 ppm, 18-30 dGH
* Very hard >530 ppm, >30 dGH
Making my water officially "moderately hard". However I've tested my water a couple of times and the conductivity was about 800 microS, (possibly because these official ones are an average, and you don't know the range of the readings), which would take it well into the "hard" category.
cheers Darrel
Hi all,
Irene wrote: "Also i noticed tds is often measures in different units, not just ppm, so you need to know what you are measuring it in too."
I agree it is a bit of a nightmare trying to get all the units sorted out. I'll have a go, and treat TDS and hardness as the same (they aren't exactly, but I'll explain why as I go a long).
TDS is total dissolved solids and hardness is a measure of dissolved multivalent minerals (Ca2+, Mg2+) in the water (multivalent just means there is a number in front of the +, e.g. Ca2+).
There are 2 types of hardness "temporary" where boiling will remove them - carbonates, usually calcium or magnesium, and "permanent" which can't be removed by boiling - sulph(f)ates, chlorides e.g. magnesium sulphate ("Epsom salts").
In the UK hardness is usually a measure of the calcium carbonate (the lime(stone), chalk or scale) content. The equilibrium reaction is:
CaCO3(solid) + H2CO3(aq. in solution) ⇋ Ca2+(aq) + 2HCO3-(aq) (exactly same for Mg2+ as well, so both Ca and Mg are usually added together and expressed just as calcium)
As you heat the water CO2 becomes less soluble (it's not in the equation as CO2, but bicarbonate is - 2 x HCO3-) which moves the equation from right to left (less CO2 means less bicarbonate ions HCO3- to balance the Ca2+ ions), Ca2+ can't remain in solution and are precipitated out as the "scale" (CaCO3) in your kettle, immersion heater etc.
Ion exchange resins (water softener) can remove both types of hardness by exchanging sodium (Na+) or potassium (K+) for the calcium and magnesium (but you would still have high conductivity and TDS).
As a further problem most hardness tests actually test the conductivity (and therefore the TDS - amount of "salts" - as ions, for sodium chloride Na+ Cl-) this can be slightly misleading as monovalent ions (Na+), don't contribute to the hardness, but do contribute to the conductivity (and TDS).
But here goes - a few equivalents first:
Parts per million (ppm) is the same as milligrams per litre (1000 cm3 in a litre, which for water weighs 1000g (a kilogram), 1000 milligrams in 1cm3 which weighs 1 gram).
Parts per billion (ppb) is micrograms per litre (1000 micrograms to the milligram).
mmol/L (millimoles per litre)
One millimole of calcium (either Ca2+ or CaCO3) per litre of water corresponds to a hardness of 100 ppm or 5.61 dGH, since the molar mass of calcium carbonate is 100g/mol (Ca has a RAM of 40, C = 12 and O = 16, CaCO3 = 40 + 12 + 48(16 x 3) = 100)
100g in 1 litre is a molar solution of calcium carbonate (40% Ca), and 0.1g per litre a millimolar solution.
General degrees of hardness is the same as German degrees (dGH).
1 dGH is "One degree German" and defined as 10 milligrams of calcium oxide (CaO) per litre of water. This is equivalent to 17.85 milligrams of calcium carbonate per litre of water, or 17.85 ppm. (look up American, Clark, French degrees etc. on Wikipedia for a conversion).
As an example my tap water (Corsham, Wilts - SN13 9AR) is (go to your water company in the UK and you can get average water figures for your postcode).
Calcium (milligrams per litre) 119 (298 x 40% = 119)
Calcium carbonate (milligrams per litre) 298
Degrees German (ºdH) 16.7 (16.7 x 17.85 = 298)
Degrees French (ºf) 30
Degrees Clark 21
Sodium (milligrams per litre) 22
Conductivity 615 micro S(iemens)
Descriptions of hardness correspond roughly with these ranges of mineral (Ca, Mg) concentrations: (pinched straight from Wikipedia)
* Very soft: 0-70 ppm, 0-4 dGH
* Soft: 70-140 ppm, 4-8 dGH
* Slightly hard: 140-210 ppm, 8-12 dGH
* Moderately hard: 210-320 ppm, 12-18 dGH
* Hard: 320-530 ppm, 18-30 dGH
* Very hard >530 ppm, >30 dGH
Making my water officially "moderately hard". However I've tested my water a couple of times and the conductivity was about 800 microS, (possibly because these official ones are an average, and you don't know the range of the readings), which would take it well into the "hard" category.
cheers Darrel
wow, thanks for that.
glad i did A level chemistry. do I take it you are a scientist of somekind?
glad i did A level chemistry. do I take it you are a scientist of somekind?
Hi all,
Irene I look after a small ecology lab (now mainly computer based) at one of our smaller universities. I'm not really a chemist (I trained as a botanist), but we do quite a lot of work with water quality and leachate from landfill.
cheers Darrel
Irene I look after a small ecology lab (now mainly computer based) at one of our smaller universities. I'm not really a chemist (I trained as a botanist), but we do quite a lot of work with water quality and leachate from landfill.
cheers Darrel
converting TDS to Conductivity is almost the same as miles to kilometers
Hi all,
I forgot one thing when I posted this, and that was that "Total Dissolved Solids" (TDS) can be converted into conductivity (in micro. S.) by multiplying by 0.64.
Therefore:
64 ppm TDS = conductivity of 100 micro S, and 100 ppm TDS = 156 micro S.
Which might not sound very useful or easy to remember but the conversion factor for miles to kilometers isn't far different (0.62) (100 kph is 62 mph), so that will give you a figure that is pretty close.
cheers Darrel
Hi all,
I forgot one thing when I posted this, and that was that "Total Dissolved Solids" (TDS) can be converted into conductivity (in micro. S.) by multiplying by 0.64.
Therefore:
64 ppm TDS = conductivity of 100 micro S, and 100 ppm TDS = 156 micro S.
Which might not sound very useful or easy to remember but the conversion factor for miles to kilometers isn't far different (0.62) (100 kph is 62 mph), so that will give you a figure that is pretty close.
cheers Darrel
Irene I breed L134, L333, L270, L260, L397, L202, L002 and many more and I have never measured my TDS I do what I do to one tank to them all. Water changes 10% every second day and on the alternative day feed the fish. lealea
thanks lealea, sounds like you have good water then. the water here in Norfolk is pretty awful. interesting you feed every other day, is that just the adults or the fry too? I fed my tanks quite often as i think the fry need it (but dont actually know)
The Fry get fed every day. It is my breeders and subadults that only get fed on a second day basis. lealea