I started WaniKani on February 22nd (54 days ago) and just got my first enlighted radicals (YAY!!!). I’ve lived in Japan for over three years now and for the first 2 3/4 years, focused mainly on learning conversation and new spoken vocab- I’m daily life fluent. I naturally learned kanji through daily life, but then on recommendations from friends, started WaniKani. I’m currently on level seven. The first few levels were so easy and I breezed through with high accuracy. Now even if I know the vocab conversationally, I don’t recognize the kanji so my accuracy isn’t as high. I typically do 21 new lessons a day- focusing on the radicals and then kanji when I first level up. Usually as I finish a level, I don’t have many new lessons. But when learning the new radicals and kanji at the beginning of a level, my accuracy is so low in the beginning (around 70%). What do you recommend- should I lower my daily limit of new lessons to focus on higher accuracy? With my schedule, I typically am able to spend time on WaniKani throughout the day- morning, afternoon, and evening. Please give adivce!
It’s all gonna be a personal journey for you. I aim for 10/day to keep reviews manageable for myself. If its demotivating for you to have such a low accuracy then definitely slow down, efficiency and speed mean nothing if you fall off.
If the low accuracy doesn’t bug you and you’re okay with your current workload then its probably fine, it’ll increase again in a few months so do keep that in mind.
I personally also get a lower accuracy on most my first kanji lessons, but usually get it up higher in my afternoon review. A single small session of lower than average accuracy doesn’t bug me at the end of the day, so I’ve just kept at it. SRS I feel keeps me on track enough.
An overall lower accuracy on other reviews would be a sign to slow down to me, but the first review of new items is not. It’s just part of the process
Personally, I recommend (if you have plenty of time, which it sounds like you do) just spending more time when learning kanji. Usually the reason you don’t remember an item is because you only glanced at it, and only long enough to pass the lesson review - you want to be able to really know what to look for, and ideally you should be able to write all 5 kanji you reviewed within the minute after the review batch.
On the other hand, you could just send it through Apprentice 1 twice and it’ll come out fine - you won’t understand the kanji worse just because you had to review it more. On the other other hand (why do I have three hands) that’s not very satisfying and can feel like you’re throwing several sharp kanji-shaped objects at your brain until they’re stuck like pins in a pincushion… well whatever works 
21 lessons a day could be considered a lot
At some point they’re gonna roll back around and you’ll be doing 300 reviews per day. I guess that’s up to you to decide if it’s too much or not
I did 10 lessons per day when I was using the site and it was around 100-150 review per day max with a successful rate around 90%