Hi all,
Filtration material
Coarse sponge and/or ceramic rings for me too.
Peat Bogs
Buy peat while you can, it is fast running out. I've got a new slogan for the "
Peat Producers Association" (should arguably have been called the "
Peat Exploiters Association", and I've just found out they are now called "
The Growing Media Association"
http://www.growingmedia.co.uk/).
A nature reserve in a bag for your garden (or aquarium)"
More peat details here:
<
http://www.rhs.org.uk/Gardening/Sustainable-gardening/Peat-and-the-environment> & <
http://www.naturalengland.org.uk/about_us/news/2010/180310.aspx>.
If you are worried about the air miles involved in transporting "Indian Almond" leaves from SE Asia, Alder cones (
Alnus spp. - A. glutinosa, A. cordata or A. incana) are a very good alternative for adding tannins, and can be collected locally by most people (possibly even Luis in E. London).
pH
I believe pH is but a number which is rendered by most test kits in direct relation to minerals in source water or lack thereof.
I see where you are coming from, but this is not necessarily true, pH is a fairly meaningless measurement without some measure of the carbonate buffering of the water as well. The technical details are here: <
http://www.ukaps.org/forum/viewtopic.php?f=51&t=14695#p152255>.
This means that not all pH values are equal. I use rainwater in my tanks and in the afternoon when the plants are photosynthesising I might record a pH in the pH7.8 - pH8 range. This is not the same situation at all as in hard, highly buffered carbonate rich water (like my tap water) that will also have a high pH of somewhere around pH7.8, but one that is stable, whatever you add to the hard water, within reason, the pH won't change very much. If I measure the pH of the hard buffered water in the morning before lights on it will still be pH7.8 ish, however if I now look at the pH of the rainwater tank it will be somewhere around pH6.5, my water has magically gone from alkaline to acid over-night.
In the rain-water case I know I don't have much buffering, so the pH differences are attributable to the amount of dissolved CO2 (as carbonic acid) in my water and the carbonic acid/carbonate equilibrium. In comparison the large reserve of buffering of the hard water, the dKH value, mean that only the constant addition of CO2 will drive the pH down from its stable value.
However although pH is a fairly meaningless measurement in very soft water (for both aquarium keeper and aquarium residents) TDS is not. I know from experience that if I keep the TDS in the 70 - 120 range (by altering teh proportion of rain/tap water), my water will be about right for my largely S. American fish and I can ignore pH. If I wanted to breed extreme black water fish, I would need to start from a lower TDS value, and then reduce the pH with weak acids (which will then increase the TDS). In this case pH would become relevant.
cheers Darrel