Haven't seen you on here in a while... Welcome back!

I'll take a crack at what I think may have been going on and is going on in your pond...

Because the crappies in your pond were stocked after it was established they didn't have a head start on your bass. In new ponds, crappies are often stocked at the same time or even before the bass. This means they get a head start on the bass and this is a big part of the problem. They are quicker to reach maturity and spawn first, mean there are many many crappies born into a pond with little or no predation on the newly born crappies. In your pond, there was already a well established bass population to effectively prey upon your crappies.

Crappies spawn at 58-68 degrees F. All spawning is done in the spring.

Information on when and at what temp GSH spawn is varied depending on the source. Anywhere from 59-70 degrees F in one source to 68-80 degrees in another. However, all sources agree that spawning is can be spread out into late summer or early fall. It has been my experience that GSH do not spawn at temps in the upper 50's or low 60's. I usually see GSH spawning about when the bass are wrapping up their spawning and the BG are just starting.

It would be a large surprise for me to see GSH spawning before or with crappies.

I do not believe the GSH are having much of an affect on your crappie spawning success. I have no doubt that the GSH are providing an excellent forage base for your crappies and they make be taking pressure off your bass and sunfish fry as the crappies may be focusing more on the GSH than the LMB and sunfish fry and YOY. It has been shown in research that species like GSH do slow the initial growth rates of YOY crappies and bass. This is because GSH feed on the same zooplankton that YOY/fry crappie and bass feed on. However, once the YOY crappies and bass get to a size where they can effectively prey on the GSH themselves, growth rates improves and become better than without GSH present. Perhaps, the initial reduced growth rate by YOY crappies, means they stay in a size range where they are more vulnerable to predation by LMB meaning more are eaten?

Your 12 acre lake is rare amongst private BOWs. It cannot be compared to smaller ponds. Most smaller ponds have minimal shallow water areas and limited habitat to produce good year classes of GSH. You can stock GSH into a 1 acre pond ahead of bass. They will do well, but once the bass get stocked it's only a matter of time. Those original stockers and perhaps one or two year classes after that will do well. Then the bass predation becomes too heavy with limited shallow water areas for the YOY GSH to take refuge in. Within a few years, all you have left are the GSH that are too large for the bass to eat. They will spawn each year, producing young but all those young will be eaten in a short period of time. Eventually your first couple generations will age. GSH have a maximum life span of about 7-9 years. So, by the time a pond is 10 years old, the GSH will have died out.

Your lake is different, it contains suitable spawning and rearing areas for GSH. This means you have a naturally reproducing and maintaining GSH population. There are some smaller ponds that have the right conditions, but they are the exception rather than the rule.

I think the biggest factor is why your crappies haven't gotten out of control is they were stocked after the bass were well established and they have a self sustaining forage base to feed on. Had the crappies been stocked before or with the bass, you'd see a very different outcome.