Just curious if anyone has fed their fish with shrimp, fillets, other that contains salt and/or sodium tripolyphosphate for a long period of time. Pretty much all I find contains these preservatives. I am wondering if it is necessary to avoid these preservatives. I fed my fish shrimp with tripolyphosphate and salt for a long time. The fish had good growth, and I didn't experience any problems. Then I read a thread discussing these preservatives are bad for fish, so I have avoided them since.