Using Pineapple to Run-In a Concrete Pond

This is an email i received recently from a blog visitor.

Hi Jeff,

I have just completed my koi pond. My contractor told me to "put in pineapple skins" into the koi pond for a few days to "clean the pond" and rid it of toxins from cement etc.  before cycling it and putting fishes.

Is this the right way to do it ?

I guess this could be a good practice to follow for concrete ponds. Since pineapple is acidic and should reacts and neutralise the cement (alkaline) which may leach into the water over time if there is no epoxy sealant used to coat the surface of the concrete pond.  In fact, on similar advice from my contractor who built my first 2 ponds, I did put in pineapple skins into my pond water for a week or more before cleaning the pond and doing a 100% water change. I bought half a dozen pineapples and used the skins and core while we ate the flesh. Pineapples are relatively cheap in South East Asia, but I guess other mild acids can probably do the job too.

For my third pond, I told my contractor to coat my concrete pond with epoxy sealant. That will prevent cement leaching alkaline into the water. Choose black colour sealant paint. Your Koi will stand out beautifully against the black background.  In any case, my filter compartments are not coated, so I may actually need to do the “pineapples treatment” but I did not.  Maybe that was the reason I lost some of my Koi in my new pond initially. But that could be due to other causes e.g. immature biological filter or excessive water changes. Steps to introduce fish to a new pond is a topic for my blog for another day.

So, to be on the safe side, just do the “pineapples treatment” and enjoy your pineapples.