ScareCrow
Member
Hi All,
I'm in the process of setting up a new tank and thought I'd check my water providers test results as I knew the water is hard but I also wanted to check other parameters, so I had an idea for fert. dosing. The tank will be low tech with a beech/oak leaf litter substrate mixed in equal parts with cat litter and capped with cat litter. As suspected the water is hard 293ppm TDS @20°C (according to water provider. My TDS pen reads 311 at a room temp of 18°C). So I thought I'd check my rain water, 58ppm TDS (using my own TDS pen at a room temp of 18°C). This all seemed great as I could soften my hard water with rain water and everything would be great. However, I thought I'd check the pH. Tap water from provider results = 7.5pH. My pH pen tap water = 7.8. My pH pen rain water = 8.4. I thought that the high pH reading of the rainwater was due to the inability of the pH pen to measure accurately in such soft water. So I setup a few tests combining different combinations of rain water and tap water and measured them across 3 days. Below are the results (I don't have a Gh or dKH test kit, so can't provide that info but I've included what is available from the water company). The reason I question the results is that I'd expect adding rain water to my hard tap water would either maintain or slightly lower the pH but instead it's pushing the pH higher. I collected the rainwater in a bucket to remove the possibility of contamination from anything on my roof and I didn't collect rain from the first rain shower, to avoid air pollutants as much as possible. I'd really like to get you opinions on this as I've not managed to find anything or come up with a reason, other than:
1/ The pH pen is reliable (I get a fairly consistent reading +/- 0.3) but inaccurate and it was a coincidence that the water company and my own reading are fairly similar.
2/ There is something in the rainwater that really has an impact on pH.
Thanks for you time.
I'm in the process of setting up a new tank and thought I'd check my water providers test results as I knew the water is hard but I also wanted to check other parameters, so I had an idea for fert. dosing. The tank will be low tech with a beech/oak leaf litter substrate mixed in equal parts with cat litter and capped with cat litter. As suspected the water is hard 293ppm TDS @20°C (according to water provider. My TDS pen reads 311 at a room temp of 18°C). So I thought I'd check my rain water, 58ppm TDS (using my own TDS pen at a room temp of 18°C). This all seemed great as I could soften my hard water with rain water and everything would be great. However, I thought I'd check the pH. Tap water from provider results = 7.5pH. My pH pen tap water = 7.8. My pH pen rain water = 8.4. I thought that the high pH reading of the rainwater was due to the inability of the pH pen to measure accurately in such soft water. So I setup a few tests combining different combinations of rain water and tap water and measured them across 3 days. Below are the results (I don't have a Gh or dKH test kit, so can't provide that info but I've included what is available from the water company). The reason I question the results is that I'd expect adding rain water to my hard tap water would either maintain or slightly lower the pH but instead it's pushing the pH higher. I collected the rainwater in a bucket to remove the possibility of contamination from anything on my roof and I didn't collect rain from the first rain shower, to avoid air pollutants as much as possible. I'd really like to get you opinions on this as I've not managed to find anything or come up with a reason, other than:
1/ The pH pen is reliable (I get a fairly consistent reading +/- 0.3) but inaccurate and it was a coincidence that the water company and my own reading are fairly similar.
2/ There is something in the rainwater that really has an impact on pH.
Test Description | ||||||
Water Tested | Hydrogen ion (pH) | Conductivity (ppm) | °dH | Alkalinity (mg/l CaCO3) | Alkalinity (mg/l HCO3) | Comments |
Tap Water Only | 7.8 | 311 | Results are the mean of 3 days of testing at room temperature (approximately 18°C water would be colder). | |||
Rain Water Only | 8.4 | 58 | Results are the mean of 3 days of testing at room temperature (approximately 18°C water would be colder). | |||
50:50 Tap : Rain | 7.9 | 195 | Results are the mean of 3 days of testing at room temperature (approximately 18°C water would be colder). | |||
25:75 Tap : Rain | 8 | 147 | Results are the mean of 3 days of testing at room temperature (approximately 18°C water would be colder). | |||
Water Company Results | 7.51 | 293 | 16 | 163 | 199 | 0.5 conversion factor applied to get conductivity in ppm from µS/cm@20°C |
Thanks for you time.