Byron, a last very basic question to see if this is a solution to my issues or a further headache....in regard to adding a small amount of crushed coral to my filter to essentially raise Kh and Ph slightly to say...Ph 6.5 (which I would think would be suitable for soft water fish) will the crushed coral continually dissolve and keep making Ph higher and higher or is the amount added to filter going to level out at a certain point closer to my desired Ph? I understand that you are no advocate to allowing nature to be tampered with but I wonder on the actual effect that said CC would have on my mini ecosystem and it's parametres. I thought the more coral you added, the higher Ph and Kh will get...add lesser amount and it will only buffer to a certain level and hold it there?
Not sure if my thoughts are correct and would adding a tad bit of CC benefit the water parameters whilst keeping it at a decent level of Ph and Kh.
I have "buffered" a couple of times, and over long periods, so I have some experience with doing this. Back in the late 1990's into the early 2000's, I used dolomite which is calcium and magnesium. This is similar to aragonite, and both are better "buffers" than coral which is only calcium. I had 2-3 tablespoons of dolomite in a nylon bag in the canister filter of the two largest tanks, and it maintained a pH around 6.4 when the tap water was pH 5 or lower (the city did not add anything in those days). So a very little goes a long way. I experimented with the amount over a period of weeks to get to this stage, and without changing the dolomite at all it went on like this for several years. The mineral does keep dissolving very slowly, but even when I discontinued this around 2003 or 2004 there was still dolomite in the bags. The only thing here is that I have no idea what this did to the GH, or KH, as I did not test for these back then. I had soft water fish so there seemed no reason to worry about GH or KH. And the plants and fish thrived, so presumably things were fine.
Vancouver began using soda ash to raise the pH, and I removed the dolomite. I tried crushed coral, and it sent the pH soaring overnight, with only a couple tablespoons in the filters (these were 90g and 115g tanks), but the GH which I did measure this time was not raised at all. I decided this was of no real benefit, as I want acidic water, and the GH wasn't being touched so the plants would not benefit. One of my reasons for this experiment was the plants, lacking calcium. I changed to aragonite, but the pH still soared, so in the end I stopped and let things go where they wanted. I am certain that my significant weekly water changes work to maintain a more stable water chemistry.
All you can do is try it, but not with fish or shrimp in the tank as you can easily have massive fluctuations and this is what damages fish. A stable pH, be it higher or lower than what you might prefer, is generally safe as fish at least will manage provided it is not extreme of course. Use very, very little. And remember it takes a couple of days for changes, at least it did in my situation but I may have had a more stable biological system to begin with as the tanks had been running for a few years.
I read your last post and understand it perfectly but what worries me is the huge fluctuations in Ph which may occur with water changes etc, in such a small amount of water...
This is very unlikely to occur, the pH fluctuations I mean. I use pH 7.0 tap water doing a 50-60% water change on tanks with a pH of 5 (or perhaps below, kit doesn't measure below 5) and the most the pH changes is by two or three decimal points. I've been doing this for years with no ill effects on the fish. These tanks range from a 10g, to a 20g, a 29g and a 33g. My three larger tanks have a higher normal pH, around 6.0 to 6.6 for some reason. As I think I said earlier, every aquarium will develop its own biological system, and remain relatively stable unless you impact it. Regular partial water changes are part of the system's stability.
PS so how does the tank manage waste from the fish in such acidic water, I understood that in such conditions, ammonia is turned into ammonium which is not toxic to fish, but what about nitrites? how are they managed if not by beneficial bacteria? plants in tank maybe? nitrates obviously are taken out with weekly water changes.... If BB are not around in the filter at such low Ph and Kh values, what actually detoxifies the waste from the occupants?
I have plants, if only floating, in all my tanks. Plants readily use ammonia/ammonium, and obviously nitrite is not a by-product when plants take up this ammonia/ammonium. Some bacteria will establish. I have never had a tank with very soft acidic water without plants, so I have no personal experience as to what may be different, but I would suspect the nitrifying bacteria are still doing their thing. However, pH crashes are obviously more of a worry, and if the fish load is beyond the tank's capacity trouble will easily follow.
