I boiled mine for about 4 hours and changed the water when it got to look like strong tea, about 5 times. It has been in my SA/Ca tank a couple months now and it still leaches tannins. The fish are fine but after 3 or 4 days you can see a color change in the water. I read someplace that you never really get all the tannins out . Adding wood does look great in a tank thou.
i generally suggest the boiling method, but did it for a good 10-14 days. i would much rather wait to get 90-100% of the tannins out rather than only give it 3-4 days and have brown water for months
Yeah I used malaysian and it leeched so bad. I couldn't boil the pieces even in the 5 gallon pasta buckets we have. I just use scalding hot water out of the faucet and soaked it in that over and over and let it dry out and did it again, and not for some reason it doesn't leak at all.
I mean there was a point in time where I had water that was about as dark as coffee.
I wanted blackwater, but I underestimated the humic acid. Boy was it brown.
each of my mopani pieces were soaked 10-14 days each. I added a few too many at once and the cumulative effect was just as bad as one non-soaked piece. Needed to do a weekly w/c just to keep the water somewhat clear.
I've been boiling 2 pieces daily for 11 days now (2 hours of boiling, then let it sit the rest of the day), the water still comes out looking like tea. I'm in no hurry to get them in the tank, so I figure another 2 weeks or so can't hurt!