How to make your own Cliffs

Huapala they do but if you use pond sealer or other non toxic concrete sealer and seal the entire thing with 3 or 4 coats it wont leach into your tank at all and as soon as the sealer is cured you can drop it right into your tank
Yes Joseph Huntley Joseph Huntley you are right and non toxic concrete sealer https://www.pondpro2000.com/pond-sealer.php is the best option to use.
 
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