Yellow crispy fan leaves on 4 different strains.Deficiency or hard water?

[stefanosstef]

Could be as simple as needing repotting. Get a troubleshooting form filled out. I don't think you have a serious problem....yet.....lets figure it out before you throw everything at it.

Is it easy to repot in same size pot?I imagine it as really root disturbing.I can't use bigger pots because there is not enough space in the growroom.

If you can't afford a $7.00 freswater aquarium ph test kit, you can google your local water quality report, which should have pertinant information about your local tapwater.
But Like Washougal said...please copy-n-paste the troubleshooting form here, and fill it in as best you can. (no guesswork...if you don't know, just say so)

I'm in a small town and finding cheap ph strips is not easy.Last time I only found in a pet shop and I payed 20â?¬ for 20 strips measuring ph and EC, I found my company's site though.I'm not sure from what source I'm taking but I lowered them to 2.So, PH: 7.75 for source A and 7.68 for source b.EC:433 μS/cm for A and 427 for b.

Your Equipment:
.1) Type and wattage of lights. Hps 400 watts
.2) Distance from tops? 45cm
.3) Reflector type? cool tube set-up
.4) Is there a consistent fresh air supply?I am using a pc fan of 110cfm for outtake and leave the closet doors opened, so passive intake.
.5) Do you have an exhaust fan and a circulation fan?A fan out the closet hitting the tops.
.6) What are the bulb wattages, kelvin ratings, and schedule?12/12

Your medium:
.7) Specific brand and type of soil.soil, slightly fertilized and added perlite (not much).I put some rocks in the bottom of the pots for better drainage.
.8) Size of container.13L
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings?No

Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting?Tap water of ph 7.7
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...)
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...)I am not adjusting
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule.Biogrow (8-2-6), Biobloom(2-6-3.5), Alg-A-Mic(0.1-0.1-0.1 + trace elements).Feeding every 10 days.Have fed them twice.First time Biogrow 0.7ml/L.Second time Biogrow 0.9ml/L and Biobloom 0.9ml/L.Today I fed them with Biogrow 1ml/L, Biobloom 1ml/L, Alg-A-Mic 1ml/L and 0.5ml/L of a ph down which contains 4-18-0..I think I overdid it on phosphorus this time.
14) How often are you watering between feedings, and how much per watering?About 2 times a week, 0.5L on each pot.
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...)No
16) Are your ph levels stable, or do they fluctuate?
17) What is your ingoing water's ph? ...your runoff ph?On regular waterings ph about 7.7
18) Do you foliar feed? If so, with what, how often, and at what time do you spray?No

Your growroom:
19) Indoors or outdoors?Indoors
20) What size of closet, room or hut?60cmx90cm.Height 160cm.
21) What are the temps and humidity levels while lights are on? ...With lights off? Lights on 27-29C, mostly 28.5-29C and hum 30% lights on.Temp drops to 20-21C lights off.
22) Have you seen signs of insects in the growroom?No, never had.

Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) One sativa dom, 2 indica dom and one 60%-40%.
24) From seeds or clones?Seeds
25) Is this an autoflower strain? No