Hi chinamon,
After growing chiles hydroponically for several years, I can recommend a PH from 5.8-6.3 as ideal. In fact best is to get it down to just under 6 and let it go somewhat over 6 before you correct (or replace nutrient). A standard EC would be from 1.3-1.8, depending on plant size, kind, specie or pod size. Your Jalapeños are supposed to be a fast growing variety with a rather big pod size and for them I'd say to go up until 1.8. Convert to your ppm by the appropriate factor in case. More important is to choose the right nutrient that focusses on Potassium as for tomatoes or night shade (no vegetative or lettuce formula). Start your seedlings with 0.5-0.8 mS/cm and increase gradually. Any product that comes close enough to:
N=160-180 ppm
P= 30-50 ppm
K= 250-280 ppm
Ca= 150-180ppm
Mg= 35-50 ppm
S= 50-90 ppm
+All needed trace elements
-is suited for hot peppers and as well as for your Jalapeños. In case you are not familiar with elemental ppm, ask the manufacturer, he/she is supposed to be.
Anyway, make the total of the ppm in the formula, add 10% and you'll see that you stay clearly under 1000 ppm. No need to feed any higher concentration, just trust me.
As for replacing or toping off, there is in fact no such thing as a standard procedure. All depend on evaporation/consumption, PH and EC fluctuations. You either have a smaller reservoir and replace the whole content every week, or have a larger and top off and/or replace only after about 2 weeks (+). The more PH and EC fluctuations you have got, (which is most likely to happen with a smaller reservoir), the more you have to correct PH and EC. Much of the PH sability will depend on your tap water quality anyway. If the PH is too high (after adding the nutrients) in the first place, think of using different water.
Work out your own nutrient strategy according to your water quality (PH), reservoirs size and consumption/evaporation in ways you have not too much fluctuations - but do not need to step in too much either.
Cheers,
Lucas