Hydroponics is not “plant it and forget it”, but it is not rocket science either. The routine boils down to a handful of steps that always come in the same order. This is the yearly plan for a tower with 32 planting sites and a 40 or 50 litre tank — with numbers instead of generalities.
Weekly: level, EC and pH
Plants pull water out of the tank faster than nutrients. In July, with 20 mature lettuces, a tower loses 4–8 litres a day — a 40 L tank is half empty in three days. In April or October the same tower uses 1.5–3 L a day. The larger 50 L tank buys you roughly two extra days between top-ups in practice; no more, no less.
- Level: never below the point where the pump is still fully submerged. A Sicce pump running dry is damaged in minutes, not hours — the impeller and bearing go first.
- Top up with water that has stood at room temperature. A 10 °C gap to cold tap water is a real shock to the roots.
- Measure EC before topping up, not after. If it sits more than 0.3 mS/cm above target, add plain water only, no nutrients.
- Check pH twice a week. Lettuce and herbs like 5.5–6.5; correct only once the reading leaves the 5.2–6.8 band.
- Look at whether the top row is dripping. If it is not, the pump filter is clogging — that does not wait until next week.
Every 2–3 weeks: the whole solution out
Topping up with water consumes the macronutrients, but the salts the plant barely takes up — sodium, chlorides, sulphates, calcium from hard water — stay behind and accumulate. Your EC still reads 1.4, except that is no longer the same composition it was on day one. So: full change every 2–3 weeks, and every 10–14 days in heat above 25 °C.
- Pump off, drain the solution. It is excellent for plants in soil — just not into the same pot every time.
- Wipe the walls with a soft brush while they are still wet; a dried-on film is three times harder to remove.
- Fill with clean water, then add nutrients, then measure. Never the other way round.
- Write down the date, with a marker on the tank or in your phone. Without a date, “every two weeks” turns into five very quickly.
Monthly: pump and flow
The pump is the only moving part in the system and the only part that genuinely fails. Cleaning takes ten minutes and stretches its life from roughly one year to three to five.
- Take the pump out, open the front cover and pull the impeller (the magnet with the vanes).
- Soak impeller and housing for 20–30 minutes in vinegar diluted 1:3. That dissolves the limescale you get from water at 15–25 °dH, which covers most of Croatia and much of Central Europe.
- Remove slime and broken root fragments with an old toothbrush. No detergent, and definitely not in the dishwasher.
- Rinse twice with clean water before it goes back in.
- Check the cable: not pinched by the lid, not sharply kinked anywhere.
Between two crops: deep clean
Once the last lettuce is out, broken root pieces, algae spores and a biofilm remain in the lines. A new seedling entering that water starts with a handicap. Budget 45–60 minutes, once per batch — with leafy greens that is roughly every 6–8 weeks.
- Remove all net pots and root debris; they are the biggest source of rot.
- Flush the system with 3 % hydrogen peroxide, 100 ml per 10 L, circulating for 20–30 minutes.
- Drain and rinse twice with clean water — a young seedling will not tolerate that concentration.
- Soak net pots and caps in the same solution, rinse and dry them in the sun.
- Leave the tower empty and dry for 24 hours before replanting.
Clay pebbles can be boiled and reused. Rockwool and starter plugs are single use — everything the old root left behind stays inside them. Details are in Substrates.
Autumn and winter: ice is more dangerous than UV
The PETG the tower is printed from handles outdoor conditions far better than PLA. UV changes its gloss and shade over the years, but the structure carries through several seasons. What can actually crack it is ice: water expands by around 9 % when it freezes, and that pressure goes straight into the wall and the joints. So the tower is not shut down by date, it is shut down by forecast.
- Once night temperatures drop below +3 °C — in Central Europe usually the first half of November — the system goes out of service.
- Drain tank and lines completely. Tilt the tower so the residue runs out of the bends; that is exactly where ice cracks things most often.
- Wash the pump, dry it and store it at +5 °C or warmer. Coil the cable in wide loops, no sharp bends.
- Leave the caps on the planting sites so no water or leaf litter gets in.
- If the tower stays outside, put it against a wind-sheltered wall and at an angle so rain cannot pool inside.
The alternative is running it indoors over winter. With LED lighting the tower works in January too — it just needs light that the sun through a window cannot supply, which is covered in Lighting.
The whole checklist in one place
| Interval | What you do | Time | What you need |
|---|---|---|---|
| Every 2–3 days (summer) | Check the level, top up to the mark | 2 min | Canister of standing water |
| Weekly | Measure and correct EC and pH | 5 min | EC/pH meter, pH down |
| Weekly | Check that the top row drips | 1 min | — |
| Every 2–3 weeks | Replace the entire solution | 20–30 min | Hose, bucket, nutrients |
| Monthly | Strip and clean the pump | 10 min | Vinegar 1:3, old toothbrush |
| Monthly | Wipe out the tank walls | 10 min | Soft brush |
| Between crops | Deep clean with peroxide | 45–60 min | 3 % H₂O₂, brush |
| Autumn, below +3 °C at night | Drain everything, pump indoors | 30 min | Bucket, cloth |
| Spring | 30 min test run before planting | 15 min | Clean water |
Added up over a year that is roughly 12–15 hours of work. Less than a bed of the same area and with no weeding at all — but not zero either, and that is how you should count it before buying.