"~ jan JJsPond.us" wrote in message
...
Cement blocks like pavers or cinder blocks?

Definitely not cinder (I don't think).... more like cement block, but they
have more holes, decorative? You can see them at my website by clicking on
*Lily Pond Photos*

I've looked at your site before, but had forgotten the Lilly Ponds. Very
attractive, but I see how they might continue to leach with all the
decorative area. But after 5 years, I would think the concrete would have
aged enough.

I would have assumed that
anything underwater would have sealed over and anything above would have
aged sufficiently. Maybe the acid washing is keeping the blocks porous
and
the leeching continues.

Could be. I quit putting acid in, added 4 lbs. of baking soda and then did
4-6 water changes of 20-25% over 10 days (this was recommended by the
experts on the KHA board) it worked. Plants were happy after that. Frogs
never were bothered, amazingly. ~ jan

Oh, the acid went in the water. Still, isn't acid etching what one does
to open the pores of concrete for adhesion of various coatings? But, you
obviously know what you're doing and how to correct the problem if it
continues.

http://users.owt.com/jjspond/