john_ny

One of the things that I used, when I had an aquarium fish import business, was vinegar. We had large concrete pools, in a greenhouse that had been used to produce little plants, for the Woolworth 5/10¢ chain, befpre we moved in. The concrete benches were alkaline, and it was too expensive to use the usual "Aquarium ph reducer", so we used things like vinegar (If you look in the stores, you can find vinegar, at double the strength, (percentage) for just a little more money. In extreme cases, we used plain acid, like muriatic, that is normally used to clean new concrete, or plain old battery acid, from an auto parts store.

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John