The pond looks great, the koi are happy & healthy, but what is this sticky stuff on the bottom of my feet??
My pond is about a year old. It is pretty small - 1800 gallons. Filtration consists of a 30" Hayward and 5100 gph pump. The liner is a Firestone product. I have 14 medium sized koi which are thriving. (Yeah, I know, I need to get rid of a few. But it is so difficult to pick the castaways!) And the water clarity is excellent. The pond gets no direct sunlight, but a great deal of filtered sunlight. The location is central Florida.
About a month ago I was in the pond doing basic maintenance on the above water plants (which can only be reached by getting into the pond) at the opposite border of the pond. When I got out of the pond I noticed a large accumulation of a very sticky residue on the bottoms of my feet. The residue was very similar to the sticky adhesive on duct tape. And it was very difficult to remove. Soap and water and a scrub brush would not remove the residue. I had to use a rag soaked in mineral spirits to remove the residue. What's going on?
I had been in the pond countless times over the previous 8 months without a problem. At my old house I had a small, overstocked pond and over the course of 4 years never had a problem with the pond liner. I have no idea regarding the materials used in the pond as it was built by a different builder. The guy who built my current pond has discussed the issue with his supplier and others in the business who can provide no insight, and my pond builder has never had a similar issue with any other pond he has built or maintains. (For the record, I have a great deal of confidence in my pond builder. He is a very honest and experienced guy. He has always been very responsive to any issue I've had in the past.) My builder did note that my pH was quite low (I think he said 5.5) and I have since been doing some large water changes to bring it up. (As an experiment I soaked some leftover pond liner pieces in vinegar for 3 weeks, and it had no affect on the liner.)
When I wipe my finger or a cloth across any part of the submerged liner (pond bottom or walls) I get a small accumulation of yellowish, sticky residue. It is not black or gray. Also when looking at the pond, there is a barely noticeable pattern of hundreds of grayish circles about 1" - 4" round covering the liner. It has the appearance of encrusting lichens found on some rocks. I'm not sure how long this pattern has been present. Could this be some kind of algae which is colonizing my liner? Could it be that when I walk across the algae it accumulates on the bottom of my feet? But I just can't imagine that simple algae residue would be so darn sticky and adhere to my feet and only come off with mineral spirits?? Like I said, I never had this problem with a previous pond.
Oh yeah, one other thing, but I can't see how it could relate. My koi spawned about 4 months ago. What a mess! But after several water changes over the course of a few weeks, the water was back to crystal clear.
I love koi and this hobby, but I am very inexperienced compared to all of you. I hope that some of you can provide insight into this "sticky" issue I have with my pond. Thanks so much.