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 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

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

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
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