Yep, cure #1. One "LEVEL" teaspoon to 5 pounds of meat. If using a high resolution gram scale (one with 1/100th of a gram resolution), you want 5.7 grams for 5 pounds, or 1.13 grams for 1 pound of meat. Dissolve it in some warm water and then mix the water in your meat if making sausage. A pound will last most people several years as you only use a little bit. It does not really expire as long as it's kept dry and in the pantry.
If you don't have a scale that will show 1/100th of a gram, I recommend you buy one. They run $20-25 on
Amazon. This is mine. Find out what size calibration weight the scale you buy/have needs and make sure to get one of those also. I check calibration with my 100g weight after turning it on. If it's OK, then I measure my spices. And at the end before mixing the spices, I check the calibration weight again. If it's still 100g you can be confident the spices were weighed correctly (assuming I read my recipe correctly, I must confess I've goofed that up at least once).
The basic cure used for hams, turkerys, fish, smoked sausage. 6.25% sodium nitrite is the ratio of actual cure in the mix. One pound is enough for 400 lb of meat. Use 1 oz per 25 lb of product or 1 level teaspoon per 5 lb product. Also known as Pink Salt #1, Instacure, Prague Powder #1, Sure Cure, Modern Cure, Speed Cure.
"Tender Quick" is *NOT* the same product as this (Cure #1) and has a totally different cure percentage and more salt in the base. There are some recipes which are for "Tender Quick" and they should list that in the recipe. You do not substitute Cure #1 & Tender Quick "one to one" as they are different products. Also some recipes will call for cure #2. That is different also and usually used in a sausage or snack stick that will be fermented over time.