Hosur Aquaponics Research

Everything learned so far, gathered in one place and updated as the terrace project grows.

Terrace project

The current build on the first-floor terrace in Hosur.

1000 L IBC fish tank, drained by a solids lifting overflow (SLO) into a bridge tank.
Three 250 L grow beds cut from IBC tanks, each with a bell siphon, and one IBC sump.
1.25 inch PVC plumbing that dips under the pathway between the tank and the beds.
A new 600–700 L system planned on mineral (tanker) water.
All-male GIFT tilapia from Barur (KBCeSA).

1000 L IBC fish tank, drained by a solids lifting overflow (SLO) into a bridge tank.
Three 250 L grow beds cut from IBC tanks, with bell siphons, plus one IBC sump.
1.25 inch PVC pipe throughout, on a first-floor terrace.
A planned 600–700 L system using mineral (packaged/tanker) water.

For the 600–700 L system, test GH (general hardness: calcium and magnesium) of the source water before filling, and again during the first weeks.
Hard water leaves mineral scale and pushes pH up. Mixing or diluting it gives steadier readings.

Period	Unchanged (hard) water side	Mixed water side
Month 1	Little visible difference yet	Little visible difference yet
Months 2–3	White scale building up on surfaces, pipes and media, and pH drifting upward	Clean surfaces with stable pH and GH readings

The lorry delivers on the ground floor, but the setup is on the first floor, about 5–6 m of lift.
A siphon won't work: it only moves water downhill, so the source has to be higher than the destination.
A 12 V transfer pump isn't enough for a 5–6 m lift at a useful flow.
Recommended: a mains-powered self-priming pump of about 0.5 HP from a ground-floor drum or sump, or have the lorry driver use his own pump with a long hose.
To do: find out which local lorry owners carry that kind of pump.

Bell siphon: add a 6–8 mm snorkel and a vent on the drain.
Air locks: where the pipe dips under the pathway, fit an open vent standpipe on a tee at each high point, taller than the tank water level (about ₹50). Automatic air valves cost ₹99–450 but may not seal at low pressure.
Leak: solvent-cement the tee and reducer under the grow-bed stand, and use 45° bends to reduce flow loss.
Grow-bed inlet: put it at the opposite end from the bell siphon, ideally with a spray bar above the gravel.
SLO: remove the end cap and cover the open end with 3–5 mm stainless mesh, 1–2 inches off the floor. Seal the side holes except one anti-siphon hole near the top. Keep the water 4–6 inches below the rim and clean the mesh weekly.

All-male GIFT tilapia from Barur (KBCeSA), as you only have one tank. The hormone used for sex-reversal clears within weeks, so the fish are safe to eat.
TN government seed costs ₹2–4 for fingerlings and ₹5–6 for 20–60 g fish.
Feed size: 30% protein at 2 mm for 2–3 inch fish, 3 mm from about 50 g, and 4 mm near harvest. Options are UNO (about ₹57.50/kg), Happy Feeds and Growel.
Duckweed plus pellets cut to 4.25% of body weight a day matched growth at lower cost.

Leaf lettuce paid back fastest in the Cairo study, and cherry tomatoes lost money. Use basil as a side crop.
Bengaluru restaurant prices (Hyperpure): iceberg lettuce ₹155/kg, basil about ₹140/kg. Wholesale tomatoes and coriander are low.
Krishnagiri GIFT seed scheme: register with the district fish farmers agency (DFFDA). PMMSY may end on 31 Dec 2026. The horticulture scheme (MIDH) pays 50% of a shade net or polyhouse.
Local players: Aura Greens (Hosur), Origin Fresh and Bhoomi Farms (Bengaluru buyback).