I am a strong proponent for MG Shake and Feed for Tomatoes. Mostly because 3 yrs ago I tried it and I was buried in belle peppers. I had tried growing belles for years, they never did well, always small, poor yield, usually died. One year I tried the MG and had a ton of big fruit and healthy plants. I now use it for all tomatoes and peppers.
Pam

I have heard that MG tomato food is good for peppers too.

An inexpensive, and very very good pepper fert is Espoma Tomato-tone. At the recommended dosage, even the small bag ought to last you a while, but the bigger bag costs a bit less per lb.

Home Depot and Lowes carry it, and Walmart sometimes, but in my area it sells out fast.

Here is a link that might be useful: MFR web page + data sheet

I check the data sheet on Epsoma. Other than stated N P K, it has 8% calcium and 3% sulfur. These ingredients, IMO, make it suitable for both tomato and pepper. But the amounts of NPK are very low. I would supplement it with 16-16-16.

I will use some next season.

I am a strong proponent of NOT over fertilizing peppers. If your potting media has fertilizer in it, don't add any more for germination or potting up. If it doesn't, use a very weak solution of MG or orchid fert. About 3 weeks after planting in garden, I use 10-10-10 garden fert lightly round the outside. Don't get any on the plants. I do the 10-10-10 once more about a month after that. Stop - No more fertilizer!
John A

Another vote for Tomato-Tone. Works great.

Rick