Here is some the key information that I received via email directly from cal aqua lab - Hi Will, Sorry for the late reply. We just got back from company retreat. BEP is made from natural fertile soil, as a result, there can be variations in certain properties depending on the batch of raw materials. Some batches are more fertile (ie more organic content and rich with nitrogen and minerals such as calcium and magnesium than the others). The batch you have is one such batch. The TDS increase you see are likely due to higher dissolved calcium and magnesium in the soil, and the presence of higher ammonia reflects the higher organic nutrients. Plants seem to love the more fertile batches. However, we have not tested the effect on shrimp And further - Hi Will, In that case please do not use those bags for shrimps. We get these high-fertility batches once in a while. This variation is one of the reasons we only recommend our substrates for aquatic plants. Their product description at that time is in the attached image. I was not impressed with my experience to say the least and threatened to report them to The ACA over this false advertising. The distributor should have since made sure that all Aus suppliers have removed that description. Nb I had purchased my substrate at the end of last year so perhaps there has been a good batch imported since I don't know how you'll find this out. My experience was with the normal granule size. [emoji173][emoji111][emoji445] will