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John ines ericaceous

The superphosphate in ericaceous compost is less than ji3, so surely ericaceous should have less tds, especialy as ji3 is 8% more loam. So why did big tom get more tds from ericaceous when he tried it

Its looking like both john ines mixes have just been binned in favor of genuine pond aqua soil
 
Hi all,
Big clown said:
The superphosphate in ericaceous compost is less than ji3, so surely ericaceous should have less tds, especialy as ji3 is 8% more loam. So why did big tom get more tds from ericaceous when he tried it
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It isn't quite as straightforward as that, ppm TDS (really measured as conductivity in microS, and then multiplied by ~0.6) is a measure of all dissolved salts. Some compounds will be insoluble at higher pH values, so once you get above pH7 compounds like CaCO3 (limestone) or calcium phosphate (Ca(H2PO4)2·H2O) will be insoluble.

Lower the pH and these sorts of compounds will start to go into solution, raising the TDS.

cheers Darrel
 
That's interesting Darrel. Thanks. I am wondering how that works as I have hardish tap water(Kh-8 and Gh-12) but the water comes out of my tap at a Ph of 6.6 due to extra CO2 and then settles at 7.4 once it gasses off. But the TDS isn't much different between tap and tank, possibly 20ppm difference max and that's maybe because of the extra nitrate and stuff that are in the tanks.
When I used JBL aquabasis plus it shot the TDS a 100ppm beyond what it already was in the tank without changing the Ph. The fish didn't like it one bit as it was a fast one.
 
Hi all,
sciencefiction said:
I am wondering how that works as I have hardish tap water(Kh-8 and Gh-12) but the water comes out of my tap at a Ph of 6.6 due to extra CO2 and then settles at 7.4 once it gasses off
Click to expand...
Makes sense, the dissolved CO2 doesn't effect the alkalinity or the TDS. It is at a higher than atmospheric level in the water main, probably because the water has been under pressure (and cold) and then just out-gases until it reaches equilibrium with atmospheric levels and then the pH rises as the CO2 ~ HCO3- equilibrium moves towards HCO3-. Exactly the same effect you would get when you stopped adding CO2 via a diffuser.

cheers Darrel
 
Alastair said:
The genuine pond aqua soil contains all 3 loam peat and grit so I would opt for this to keep things how you want them. I have used this previously and am about to use it again. My ph was always around 6 to 6.5 in my low tech. Never had problems with tds either directly from the soil
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Hi,
Is this genuine pond aqua soil your talking about
the one that comes in the blue and white packaging,and available from Amazon.
Just want to check I will be getting the right stuff.
Thanks
Matt.
 
BigTom said:
I only did a test run of a day or two, no idea how long it'll take to deplete. JI3 will put pH around 7.5 in my experience, and add an extra 100-200 TDS to whatever is already in your water. Obviously will vary depending on how much you use. If you're after something that won't effect your water much then the blue bag 'Original Aquasoil' on ebay is just loam and grit.
Click to expand...

Alastair said:
The genuine pond aqua soil contains all 3 loam peat and grit so I would opt for this to keep things how you want them. I have used this previously and am about to use it again. My ph was always around 6 to 6.5 in my low tech. Never had problems with tds either directly from the soil
Click to expand...
 
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