water change ph

[pcs333]

I have been reading leebco`s water change sticky, and he recommends that as well as matching sg and temp you should also match the ph to your display tank.

Is this really necessary ? if so what would be the best and easiest method to bring the ph down because my new saltwater is always much higher than my tank.

cheers

[leebca]

The question indicates that you are not familiar with the problems that a change in pH causes a marine fish and other marine lifeforms. Our marine fishes and lifeforms come from an environment where pH never changes. There are exceptions. But for the most part, these lifeforms have no mechanism to adjust to or manage a change in pH. pH changes must be very slow or none at all.

IT IS VERY NECESSARY to match the pH when you are making large water changes.

If your make up water is that far off from your tank water then there is one (at least) additional problem:
1) Either the source water is not pure (neutral pH); or
2) Tank water pH is not being properly maintained; or
3) Salt is not formulated properly; or
4) Any combo of the above.

The tank water pH is controlled by the buffering ability of the water. The buffering ability of the water is controlled by alkalinity, magnesium, and calcium. The hobbyist MUST measure these three even if the system is FO.

These three must not just be 'in range' but must be balanced. They interact with each other. They stabilize the pH at the right level, which should be very close to the pH of new water.

I have written a chart on what the measurements of these three: alkalinity, calcium, and magnesium is in order to have them in balance, in this post: What is Water Quality.

When the pH changes on a marine fish, their innate immunity is decreased, their mucous coating is adversely affected, they are stressed, and all this results in stress which opens them up to a shortened lifespan, disease, and/or parasites. Think of what this means when these stressors are heaped on the fish every time a water change is made in its captive lifespan.

To raise the pH, use sodium bicarbonate (pure baking soda) or sodium carbonate. To lower the pH use pure (no additives), clear, white, vinegar.

[pcs333]

thanks very much lee

very informative as usual, i shall keep learning.

one question . you say ph must match when doing large water changes, so does this apply if i`m doing a 10% change ? or is it not so important on smaller changes ?

[leebca]

A 10% water change shouldn't require an exact pH match. Make sure it isn't 'way off' (just so you're aware of the pH of your system). A properly buffered system can pretty much handle a small shift of pH of a low quantity of incoming water. That is, there won't be a change in pH of the whole system.

[pcs333]

thanks