Black Tank Treatment - taken off the market . . . .

boston blacky wrote:
In the past, we've used a product called 'Nature Zyme' and found it worked well in the black tank. I just learned this product has been discontinued and I'm in the market for a (good) replacement.

It came in tablet form and was purchased on line. Please let me know if you also used it and have now found a similar product (no formaldehyde and 100 % biodegradable, etc.) which works as well.

Thanks in advance.