Why is my fermentation stalling?

I have two different brews that both seem to be stalled at 1.018. They’ve been in primary for 3 weeks and1 week, but both seem to be stopped. One was mashed at 152, the other at 157. But since both are stuck at the same gravity, I’m thinking its got to be an environmental or temp issue, it is warm down there about 68. I’ve added yeast energizer, but still haven’t had any really noticeable results. Any thoughts would be really awesome, I’m stumped.

Forgot to mention they are both hoppy pale ales. so they don’t need to drop very far, but at least 8 points would be nice!

At a rest at only 157 I would expect the one to stop at 1.018 realm as you limit fermentability to around 70% using only an alpha rest. Why would you make a pale ale at only a 157F rest? The science is out there already what did you hope to gain? A sweet pale ale?

The beer using 152f I cannot help you with as you post no details.
A. Did you pitch an adequate number of yeast?( IE: starter for liquid slurry /ample dry yeast.)
B. Did you aerate your starter/ wort?
C. If not using a starter with liquid how old was the yeast pack?

Yeast needs to be in full health prior to pitching and if you pitched a yeast in poor conditions you will never “revive”(yeast nutrients/energizers) or find good performance with that pitch and will ultimately find yourself looking for a new pitch altogether or end up with high ester/ fusels and poor beer if it completes at all. I have no idea what SOP you follow in general, but I throw this out there to all that you will waste alot time and energy by just “lumping it” and hoping for the best when it comes to pitching. Energizers and nutrients are to be used for healthy yeast/ ferments to help boost performance in predicted hostile conditions such as high gravity worts/ wines/ meads.

As an aside to all this, Has it been a few days since you checked the 152 pale? In just 1 to 2 days it can drop from 1.018 to 1.012 (ish)

I was hoping to gain experience. I KNOW it would be sweeter, but having never actually tried it before I wanted to see first hand what would happen, and since I’ve never tried it before I’m in a spot that I’ve never been and wanted to know if what I was experiencing was normal, or if it was a result of the fermentation being that much higher.

Are you using a hydrometer or a refractometer?

If a hydrometer, have you calibrated it in RO/DI water?