As I read through just to familiarize myself with this forum I come across all kinds of good information that I’d no idea even related to pond topics. It’s how I learned lime products and alum are handy materials in some cases. I have been looking for a place where I can buy these two materials. Are there general outlets that commonly sell lime and alum or are these specialized retailers in only a few locations? Plus, I don’t know what demands pond maintenance and fixing require for lime use but for me it has to be lime recently burned and slaked or better recently burned and unslaked, ie. quicklime. Any help finding sources would be appreciated.

Alum is a product we use to clear sediment and/or lock up phos. Hydrated lime is used as a pH buffer.
There are conditions that warrant use of these but normally it's in a static pond with soil or excess nutient issues.

I want lime and alum both for construction and building uses. It is easily available to me here and I have even supplies on hand. But in Colorado where I'm needing some it has been difficult to find. But my searches are mostly limited to building supplies sources now maybe I should check aquatic specialties sources in Colorado and hoped some of these might be known by members.

Hydrated lime can be bought at any big box store as type S Hydrated lime. Alum in my area comes from Helena Chemical co.

It must be another difference out West. I saw a sorry looking bag once at Lowe’s a few years ago.

It's used in concrete to make a hotter mixture to cure faster.. Should be able to obtain it from anyone selling concrete/mortar in bags.

A mix is useless to me, (and I would imagine less effective in pond use too ). I know the product at the box store, limecrete, like you say, portland cement and some lime mixed in there. Hundred % lime can be demanding to work with but what it offers is unique.