What is “a bomb”, pool contractor mentioned

[cfclay]

I am on vacation and was talking shop to the pool contractors here at this rental. I asked how they go to black or severely green pools and “fix” them in just one visit or two. They mentioned mixing a “bomb” which was very dangerous. Acted like it could clean a pool, even dissolving solids left from the process…in minutes.
Like a “fire under water” they said. I’m NOT interested concocting such a thing, just curious what this is. Any idea?

 

[Donldson]

It's nothing, it's just a name they give to whatever unwise idea they have developed to kill things fast. I have one I used in the olden days, and I can say with all certainty it's a terrible thing to do to a pool so I won't even talk about it.

 

[Flying Tivo]

 

[JamesW]

Typically, it means adding enough chlorine in one dose to kill all algae from the single dose.

Some people might add a lot of acid to drop the pH to make the chlorine more effective.

Other people might add ammonia or sodium bromide if the CYA is really high.

Service companies don’t want to go through the longer process of a proper SLAM and they will try to get the process accelerated as much as possible.

In any case, these methods are not considered to be safe and are not advised.