Alistriwen;1964836; said:In alphabetical order a good list:
Aluminium, ... ...zirconium.
THe chemicals added to tap water such as flouride, chlorine and chloramine remove these elements or convert them. The natural processes going on in your tank lead to the development of said elements and minerals. In the wild these elements are leached from clay and rock and natural mineral deposits. Answer enough? Test your tap water for those elements with the same kit I got from my university and tell me how it comes up.
*Very good. Reads like a trace element replenisher ingredients list. However, said natural processes don't occur in a tank (OK, most hobbyist tanks). Common substrates such as pea gravel and colored epoxy-coated gravels leach nothing (or close to nothing) that can benefit fish in such a small environment. Hence, the recommended use of trace elements.
(I probably used the same, or similar, test kits when I was going through college)
While Im sure a few members do age water and pre-mix and heat the water up to the temperature of the tank I doubt that the vast majority do so. Rainfall also has a negligible effect on the temperature of a large body of water. Do you have any idea how hard it is to change the temperature of a large body of water by even one degree? The only time rainfall changes temperature is during deluge seasons such as those in the amazon.
*Not all fish are from large bodies of water and rainfalls can have a more dramatic effect on these smaller ponds and creeks. The inverse is also true where small water bodies can experience dramatic rises in temperature when sudden rains drain from sun-heated surrounding rock formations.
The magical alternative would be testing your water when you do your changes to see that even changing less water you will still keep your toxicity levels at 0ppm. Im not proposing that people not do water changes, just that 50% is excessive.
*Wish this magic actually existed. But, it's fantasy to expect such results in all cases. However, I do encourage frequent testing in order to have the greatest change of attaining and maintaining ideal levels.
Here you are correct. You will dillute the water on the first water change and thus will remove slightly less of whatever particular you are trying to get rid of. That said, the difference is negligible and if you still can't get it with 2 x 25% 2x 30% is still preferable to 50%.
*I'm in agreement here. I don't perform 50% changes as a rule. I perform lesser changes unless a condition exists that would overtax the filtration on a particular system (i.e: large spawns, multiple molts, etc)
BTW, I'm enjoying this discussion. Hopefully we can all remain civil as the discussion progresses.
