I have a question for you regarding the water supply. I was talking to the manager of the Waterlife shop in West Drayton and he said that due to the PH swings in their water supply they buffer the water to make it suitable to the fish they are selling, trying to reproduce the water parameters of the breeding farms. Now, the cynic in me thought he was trying to promote the Waterlife PH buffering product, and a very expensive too: 10 quid a pop to treat just 300 to 400 litres of water!
I'm cynical too, and <"I have a real problem
"> with a lot of the sellers of aquarium products, they sell cheap chemicals, at an enormous mark-up, to rectify problems that don't really exist.
If you have hard tap water the pH will be fairly stable and about pH 7.8 - pH 8.2. This value is reached because it is the equilibrium pH value for the <"carbonate ~ CO2">
buffering system at ~400 ppm atmospheric CO2.
pH will show a diurnal rhythm in a planted tank (without added CO2). During the photo-period the plants are net oxygen producers and the water is depleted of CO2, and the pH will rise, during the night all the bioload is respiring, oxygen levels fall, CO2 levels rise and pH falls.
When you add CO2 you change the pH equilibrium point, so the pH is lower. I'm not a CO2 user, but those who are will tell you that a fairly rapid change of one pH unit (down at gas on, up at gas off) doesn't effect the fish, which probably tells you all you need to know.
CO2 ~ carbonate is a buffered system, which is why we have a stable pH value, and there are other pH buffers that will maintain pH at a specific level. I've never used the Waterlife pH buffers, but they are almost certainly based on <"phosphate buffers
">, and probably NaH2PO4 and Na2HPO4.
The only thing these products do is separate you from your money.
How much truth is there in the statement that the PH of the water supply swings significantly? And if there is some truth in it, how do we protect our fish when using tap water?
You can just ignore pH, if you change some water fairly regularly you will always have hard water in the tank.
is 17dKH referring to my area? I couldn't really find the figure in the water quality report from Affinity, I guess you need to calculate that from other parameters.
The 17dKH was for Corsham where I live, but it will be a similar value for all of the water that comes from a chalk or limestone aquifer, so most of the S. and E. of England. It is back to the equilibrium value for the CO2 ~ carbonate buffering system.
CALCIUM 115 mg/l Calcium is the principal constituent of hardness (dGH).
TOTAL HARDNESS 287.5 mg/l...The recognised classification scheme we are using is: 0-75 soft, 76-150 moderately hard, 151-300 hard, 300+ very hard. Your water is hard.
Total hardness is usually expressed in terms of calcium carbonate and is measured in milligrammes per litre (mg/l) which is the same as parts per million (ppm). ....Degrees German 16.1......
These are the values you need, your dKH is 16.1
If you wan't the working for how you can work out how calcium, bicarbonate and hardness relate to one another they are in <"this post