With peppers during the growing season in 5-gallon pots, I add a liter of full-strength Foliage Pro once a week. That amount usually saturates and then allows a bit to flow out...but not too much. I fertigate slowly, around and around the pot, getting all the mix.

Josh

Hopefully you're not doing a full flush each time. There is such thing as overleaching. You only want up to 20% max water coming out the bottom each irrigation so that a fair amount of the fert solution stays up in the soil. Of course, if your water alkalinity is really high, you'll want to do the complete flush probably every few months if you're concerned about keeping medium pH down.

One cup per gallon is WAAAAY too much, especially if adding FP each watering. I use about 1/8 tsp per gal.

If you incorporate CRFs, you can probably error on the lighter side with the liquid ferts.

A cup of fertigating solution per gallon of container volume....that doesn't sound like too much to me.

Josh

Er...i guess I misread...thought he meant a cup of FP per gal of water.

Yeah I maybe shouldn't have used the word "flush". I wet until the container is "saturated" (until some water drips out the bottom). When all the containers are done I start with the fertilizing. Every 5th time on average I water a second time until water runs freely out the bottom.

Josh. "I add a litre of full-strength Foliage Pro once a week"
That is exactly what makes me wonder. Is a litre enough, to much or to little? Wont a 1/4 litre do the same job?
I once read somewhere Al mentioning he uses a 1 Gal tank to water 50 containers. I might be mistaken but that is how I remember it.
I'm wondering about this everytime I fertilize. Am I giving them to much or to little. Smaller containers don't take/need much but big containers needs more. My problem is how much is enough. I don't want to waste and don't want to underfeed. The fertilizer don't come cheap either.....!

I think it would be better to apply a lesser strength but more often. For example, instead of fertilizing with full strength every 4th time, I would rather fertilize with 1/4 strength every time.

Also, I like oxboy555's idea, not flushing and over watering. The other thing is to be able to read your plant. Nitrogen status is a good representative. Is your plant getting pale green or getting darker green ? Then you adjust fertilizing accordingly.