Lots of baby shrimp, but few adults: anyone know why?

[PineSong]

In my 10g orange sunkist shrimp tank, I've had a million babies for a few months now. Lots of little kid, big kid sizes too. But the number of full sized adult shrimp has not appeared to increase much, if at all.

I bought the original shrimp in early October, so let's say it took a whole month for them to acclimate and start breeding--some of their babies should still be adult sized by now.

My water is hard, they have cuttlebone and a variety of shrimp-specific foods, tank temp is 75 and water parameters are shown below. Any advice from those experienced with cherry shrimp is appreciated 🙂 

[Guppysnail]

They take quite awhile to reach larger adult sizes. The group you originally purchased may have been adults for awhile so grown larger. They will start reproducing at young adult sizes. As long as more young keep appearing and you are not finding losses I would not be concerned. 

Edited February 25 by Guppysnail

[Cory]

ph looks a  bit low, might want to buffer it up a bit with some crushed coral.

[PineSong]

Thank you, @Guppysnail and @Cory. I have found no losses and only ever saw one molt, so I don't think they are dying. I will try harder to be patient. And I will see if I have any more crushed coral and if not get more. I had to buy such a large bag of it, it seems insane I could have used it all but I think that is actually the case.