I was wondering if it would be possible to use decaffeinated coffee grounds to lower the pH in an aquarium? I've looked all over and can not find any information on the subject. I did find one article talking about the impact of caffine in rivers and lakes and it concluded that caffine spikes harmful bacteria creating excess nitrate so I would want to use decaf. I'm ok with any discoluration like tannins but is there anything wrong with using coffee in a similar way as peat??