[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [APD] treating change water

On Tue, 05 Oct 2004 22:34:43 -0700, Anna R. Dunster <azzacanth at livejournal_com> wrote:

On Tue, 5 Oct 2004 20:53:09 -0700, "Steve Pushak"
<teban at powersonic_bc.ca> wrote:

pH shift does not hurt fish. Variation in dissolved minerals is what
causes osmotic shock.

should've read all posts before I replied.

I didn't know this and it's contrary to most of what I have read
online - people are always talking about being careful of pH shifts.
Is that mainly because high ph is usually associated with harder water
and vice versa?

Things on this list being contrary to most of what is online is very common. This list is nearly always right, though, even about things that everybody else 'knows' to be true.
To prevent algae, you need to reduce nitrates and phosphates.
Plants combat algae (true) by reducing nitrates and phosphates to very low levels (not so true)
pH shifts hurt fish.
Red plants need more light.
You need lots of light to grow plants (more than 2w/g).

As for pH:
pH is merely an indicator of other things. pH shift does not, in itself, affect fish.
In an otherwise unbuffered aquarium (i.e. not using acids like peat or a phosphate based buffer), levels of carbonate hardness and the amount of CO2 dissolved in the water determine pH. If you have water with a high KH (high carbonate hardness), the pH is higher for the same amount of dissolved CO2 as for water which is 'soft' and has a low KH.
But the pH swing caused by injecting CO2, and then turning it off at night for instance, does not affect fish, even though it can change pH considerably.
I'm not sure (I'm not really one of the people who knows their stuff on this list), but I don't think the level of KH is critical either. I think it is the level of calcium and magnesium, the 'true' hardness or GH, that can cause osmotic shock. These do not affect pH, however water with a high GH tends to have a high KH because hard water comes from limestone, which is CaCO3 (and some MgCO3), so the minerals are associated.
I think dropping fish from water with a high level of dissolved minerals into water with a low level of dissolved minerals is what caused osmotic shock. But assuming you buy your fish from a local shop, they will be acclimatised to the tap water already...
Doing 50% water changes every week seems to be the best suggestion that I have heard.

I have heard the best way to control your water (if you really do have hard water, what is your GH and KH?) is to get an RO unit, but it is by no means required.

Anyway I think I am getting a pretty good idea what I will do with my
tank once I am done treating for ich and start doing regular water
changes again. (my medication recommends not to change water for the
course of treatment)

My tank is usually not much warmer than room temp (the house is
generally kept in the low 70s and the tank is set to mid/high 70s)

That's the temperature I keep goldfish at; Tetras live in much warmer water than that (Cardinals are still happy at >30 for disease treatments).

It sounds as if I should be able to adjust my tank to 6.8 pretty
easily contrary to my initial impression :)   I don't mind not having
precise control.

The most important thing is this: why do you want to? pH is irrelevant to fish; and most fish will live (though not neccessarily produce fry) at pH's and dissolved mineral contents far from what they had wherever they are natural.
Consider that all plants, even those that grow in very soft water, do better in harder water. Hard water contains the mineral nutrients that all plants need. Often what is found in nature is not required (or sometimes even beneficial). Fish are very adaptable.

PS I am confident that any mistakes I have made will be pointed out! This list is surely the best place on the web for knowledgable people...

Andrew McLeod
thefish at theabyssalplain_freeserve.co.uk

This email was scanned carefully before transmission to remove any content, information or relevance.
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com