Your leaves are showing multiple deficiencies. How do the roots look? What are you feeding them? Res temp? pH level? etc.

Sorry haven't made it back out there but when I checked a few days ago the ppm was 1450. pH between 6 and 6.5. Roots looked fine then, nice and white.

Used half GH gro and bloom since there was a few flower buds starting to form.

That's good the roots look fine. Judging by the leaves they're showing Ca, Mg, and K deficiencies.

I've grown many pepper plants, currently have green chilies growing right now, and they have a real thirst for potassium especially when flowering and fruiting. Without proper levels they will drop blossoms and fruit very little.

Neither the GH gro or bloom has any calcium in it. If you're using tap water that will probably be giving it some Ca but concentrations need to be high since Ca is only taken up with water into the plant so if your plant isn't drinking much water, and it should be, then it's getting very little Ca. If you're using RO water that has no calcium, or at least negligible levels, and well water, who knows, unless you've had it tested.

There is magnesium in the mix you used but not much in comparison to what you need. Pepper plants and tomato plants need a lot of Mg.

If you continue to use just the gro and bloom then up the ratio so the bloom is at least 4 or 5 times your gro. That should help with the K and Mg but the Ca with FloraSeries is in the Micro part. Starting using that as well or supplement with a Cal-Mag.

These issues are probably the most common ones you find since most nute companies don't put enough Ca or Mg in their mixes since they're basically splitting the difference since people use them for soil as well and a lot use tap water with hydro which usually provides some Ca and Mg. This is reason many suggest using a Cal-Mag if you're RO water.

You said 1450 ppm which is really high regardless of conversion factor from EC. When I first read that I was thinking EC which would be fine but if it's actually PPM then I'd bring it down to about half that. That could explain some of the issues with Ca. Too high of salts reduces water uptake hence less Ca as well as locking out other nutrients.

I'd do a water change and lower your concentration, up the bloom, and add some calcium either with the micro part or a Cal-Mag and go from there.

Good luck.

Thank you so much for the info. Yes it's tap water. I will add the calmag and see if it helps. I think you're right, it's EC not PPM...it was very confusing when I read up on it but I believe my meter reads EC.

If it is EC then that level is fine for peppers. Fixing deficiencies isn't usually difficult but the bigger question is why did it happen. It's better to be preventative then having to fix stuff later. Don't know how often you do a res change but for flowering/fruiting plants it needs to be fairly often especially with a small res. They can drink up all the NPK in a solution in a matter of a few days and usually what's left is mostly Ca and some secondary and micros. They store some so they don't go immediately deficient it can happen quick.

I top off with NPK and a little Mg every couple days while testing EC everyday and can see when it gets depleted. Most green chile pepper plant with tons of big chilies on it will drink it all in two days, three max, and that's with the appropriate levels. So even doing a water change once a week is pushing it. I don't since I top off with nutes but most just top off with fresh water and with thirsty plants end up getting deficiencies. It's the curse of small reservoirs. Anyway, I ramble.

Thanks so much for the help! It's hard to find good hydroponic advice! One plant seems to be making a comeback...set out lots of new shoots and even a few peppers! Upped the bloom some and doing an Epsom salt foliage spray.

http://i.imgur.com/ADciq08.jpg

http://i.imgur.com/1Y6gYW6.jpg