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Interesting Test Results (IMO)

Subject: Interesting Test Results (IMO)
by Fishlady on 22/7/2011 16:08:21

As some of you know I'm in the process of setting up quite a few tanks, so yesterday I decided to test the gravels and sand I intended using in some of them, to be sure they are inert.

Yesterday morning I took four clean yogurt pots and filled one with water and the other three with water plus a small amount of each gravel (thoroughly washed first). I tested pH, gH and kH on all four containers and all four read the same.

I've just re-tested and found that one of the gravels has a pH reading .2 higher than the other three containers, and that gravel, plus a second different gravel have a gH reading 1 degree higher than yesterday. The fourth container, which has sand in it, is reading identically to the plain water.

A bit of a mixed bag there - but the sand will be fine, though I'll need to rethink the gravels.

But THIS (IMO) is the most important thing to come out of these tests. I always use RO in my tanks, so wasn't aware of what my tap water is doing with pH these days. The pot with plain water had a pH of 6.6 yesterday and has risen today to 8.2. That's a massive change in pH. The water is now effectively close to 100 times more alkaline than it was yesterday.

So this is a lesson for us all as to just how important it is to test tap pH after 24 hours standing, and to choose fish to suit that changed, true level. It also shows that it is vital to draw water for water changes at least 24 hours BEFORE it's needed. Otherwise, those carefully chosen fish will suffer a massive pH shock at every water change.