Quote:
|
Im curious to know how much the ciment will buffer your water... might want to look at that for a while before chosing fish...
|
This is an expected and serious issue since the beginning of the planning. I even consulted this matter with vivarium experts, they said no to cement at once just because they cannot wait long enough or they did not seal the cement off, furthermore it is quite bad for sensitive frogs. It is true that cement can buffer water, it is basically lime/calcium compounds turned into stone after all.
In my case, it is mixed with other ingredients to make different forms of concrete and mortar mix depending on the use of different sections. I'm going to use just plants and no frogs on the walls, so sensitivity issue is not apparent.
Upon mixing with water, dry cement will react and reach pH of 12-13 and greatly lowers to 9 or less as it is mixed with other ingredients and dries into solid mass. As it cures completely over the course of several days, the pH lowers again to 8. From this point onwards it will take a long time to reach near neutral, probably several months.
I've had cement based concrete ponds (and so many other people) with no ill effect to fish. Just prepare them well, give some time to perfectly cure, wash and bake it under the sun if possible. Sealing the concrete off will also help for folks who wanted the pond to be used ASAP. Plus it gives uniform colour to the pond lining, namely black for contrast.
Since I have the time in the world to wait (the whole house is also far from finished), probably several months, it should be OK. To speed up things I have some plans under my sleeve, like washing off with acetic acid and give good rinse, filling the pond with water and let nature works, adding some peat on the wait.
Anyway here is one of the workers doing his job on the filter, first time ever pic for a size comparison
