Bluestone pavers in the pond

by Linda
(Kalamazoo, MI)

We revised our pond this spring to make it larger, about 2500 gal. In search for somewhat flat stones, my husband was sold bluestone pavers (over a ton) which were broken and not suitable as pavers. The gentleman who sold them to him told him they were probably "the safest stones to use in a fish pond", he also said he builds ponds. So we added them to the pond along the flat surfaces and walls of the pond. We had 5 comet goldfish from our old pond which were between 6-7 inches long and added several small gold fish which were very active and seemed healthy. Within a few days the small fish started to die, and withing 4-6 weeks even the larger fish had died. Now my plants are dieing off. Even the frogs have all left the pond. The water has become more and more cloudy and a green brown color. At first we thought we had algea (before the larger fish died) and used the same algeacide we have always used along with "beneficial bacteria" sold to us by the local garden/pond center. There was no improvement in the water quality. We had put some sand, which we discovered also had some clay mixed in, into a shallow area and we think this has caused some of the cloudiness. We have very hard water with lots of iron (the same as we used before). The only thing different we can figure out is the bluestone we put in the pond. Could it be the bluestone pavers causing our problems?

Doug says bluestone pavers come in "natural" stone and a manufactured version. So if the natural form - shouldn't be a problem, it's just rock. If the manufactured form - you could have added a significant amount of lime from the concrete mix.

Get a water test! That should tell you where the problem lies rather than trying to guess about what we should do with it.

A pond turning "bad" could be any number of things - from disturbances while constructing those new edges to some kind of runoff to ??

So - get a water test and start from the basics.