Every hydroponic grower has been there: the plant that looked great last Tuesday is yellow and droopy by Sunday. Almost every failure traces back to one of these ten mistakes — and they all have simple fixes.
1. Wrong pH
The single most common killer. Outside pH 5.5–6.5, plants can't absorb nutrients even when they're in the water. Buy a $15 pH meter and check weekly.
2. Letting light hit the reservoir
Light + nutrient water = instant algae bloom. Cover any transparent container.
3. Skipping nutrient mixing
Most two-part nutrients (like FloraMicro + FloraGro) must be added one at a time and stirred. Mixed straight from concentrate, they lock out and form a sludge.
4. Overcrowding
Two basil plants per pod looks fine at week one and is a tangled mess by week four. Thin ruthlessly.
5. Too much light
Yes, it's possible. Leaves that look "bleached" or have a silvery cast are getting cooked. Raise the light or dim it.
6. Water temperature too warm
Above 75°F, water holds less oxygen and roots start to rot. Keep reservoirs out of direct sun and away from radiators.
7. Topping up with nutrient solution instead of water
Plants drink water faster than nutrients, so concentrations rise over time. Top up with plain pH-adjusted water; mix fresh nutrient solution every 2–3 weeks.
8. Ignoring root color
Healthy roots are white or cream. Brown and slimy = root rot. Brown and dry = oxygen starvation. Both need immediate attention.
9. Using tap water without checking it
Hard water and chloramines wreck nutrient balance. Either filter or let tap water sit uncovered overnight before mixing.
10. Giving up too early
Most "failed" hydroponic setups looked rough at week two and would have been perfect at week four. Patience is part of the playbook.
Frequently asked questions
How often should I change the nutrient solution?
Every 2–3 weeks for recirculating systems. For Kratky, you don't change it — that's the point.
My pH keeps drifting. Is that normal?
Yes. Plants alter pH as they absorb nutrients. Check every 3–4 days and adjust.
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