I recently received an inquiry about Pfertz fertilizers. I had never heard of the company before and now they have gone out of business. Most of the information I found when looking online was from various blogs and forums that I do not belong to and so could not respond. In case you know of someone who was using their products, let them know about aquariumfertilizer.com. We will do our best to guide to the products we carry that will match what they were buying from Pfertz.