No fresh white root tips

Likely causes, most likely first

Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.

1. PossibleLow dissolved oxygen in the root zone

   Root zoneAct within a day or twoRead: Deep water culture (DWC)

   Fix: Restore oxygen: clean or replace air stones, size the air pump for at least ~1 L/min per 4 L, keep a 2-5 cm air gap under net pots once roots reach the water, cool the solution to 18-22 °C (64-72 °F). Aim for 6-8+ mg/L DO.

   Recovery: Fresh white root tips within 3-5 days; wilting stops.

   How to confirm it

   • Dissolved oxygen check. Measure DO with a meter in the root zone, or check the system: air pump running, stones bubbling evenly, return water splashing, no dead spots. Target 6-8+ mg/L. Without a meter: if stones are clogged or the pump is undersized for the volume, assume low DO.
   • Measure reservoir and root-zone temperature at the end of the light period. Measure the solution in the reservoir and in the root chamber or bucket, at the warmest time of day. Target 18-22 °C (64-72 °F). Above about 23-24 °C (73-75 °F), dissolved oxygen falls and Pythium risk rises; below 16 °C (61 °F) uptake slows.
   • Look at the roots. Hydro: lift the net pot and look at the root mass in good white light. Containers: tip the plant out with a hand over the medium and look at the edges and bottom of the root ball. Healthy roots are white to cream with fine fuzzy tips. Brown roots whose outer layer slides off between the fingers leave a bare thread: rot. Firm, evenly tan roots with white tips in coloured solution are staining.
   • Check pumps, timers, nozzles and drippers. Watch one full cycle: the pump starts on time, every nozzle mists or every dripper delivers, NFT channels have flow end to end, air stones bubble. Clear clogged emitters and filters. In HPA, a failed pump or blocked nozzle can kill exposed roots fast, so check this first when plants on one system wilt together.

2. Less likelyChlorine or chloramine in tap water harming roots and soil life

   Root zoneLow urgencyRead: Water quality for cannabis: RO vs tap, alkalinity, bicarbonates and chloramine

   Fix: Usual tap levels rarely hurt the plant directly; the concern is living soil, beneficial microbes and young roots. Chlorine gasses off in 24 h of aeration; chloramine does not. Remove chloramine with long-contact or catalytic carbon, or about 1 g of ascorbic acid per 100-400 L, or use RO.

   Recovery: Biology recovers over weeks; seedlings resume growth within a week.

   How to confirm it

   • Get a water report (or test your water). Ask your water utility for the annual report or test well water: alkalinity (mg/L CaCO3), pH, EC, Ca, Mg, Na, Cl, B, and whether it uses chlorine or chloramine. Alkalinity above ~100-150 mg/L as CaCO3 pushes root-zone pH up; sodium above ~50 mg/L and chloride above ~70 mg/L are a problem; softened water is high in sodium.

3. Less likelyPump, timer, air or emitter failure in a hydro, aero or drip system

   Root zoneAct nowRead: High-pressure aeroponics (HPA)

   Fix: Restore flow or air immediately: check power, timer, float switches, filters and nozzles. Mist exposed roots by hand or lower plants into solution while you fix it. In HPA and NFT, fit an alarm and a backup pump; roots die fast when misting or flow stops.

   Recovery: Plants regain turgor within hours if roots were not dead; brown, collapsed roots mean rot risk next.

   How to confirm it

   • Check pumps, timers, nozzles and drippers. Watch one full cycle: the pump starts on time, every nozzle mists or every dripper delivers, NFT channels have flow end to end, air stones bubble. Clear clogged emitters and filters. In HPA, a failed pump or blocked nozzle can kill exposed roots fast, so check this first when plants on one system wilt together.

Look for

Root mass with no bright white growing tips at the margins..