Keep the tanks. Change the water.
Most of a farm’s value is in the building and tanks. An upgrade finds the one stage that limits the farm and rebuilds the loop around what you have, so you grow more without starting over.
existing tanks kept in Riyadh
project-reported density, Riyadh
delivered upgrades
first layout
25 concrete tanks stayed. The loop was rebuilt.
In Riyadh the farm already had a building and 25 concrete tanks. The owner wanted to keep them and grow more fish in the same space. We kept the tanks and rebuilt the treatment loop around them. Project-reported density rose from 20 to 50 kg/m³; the figure comes from the farm operator.
- existing concrete tanks25 tanks kept
- around the existing tanksLoop rebuilt
- 20 → 50 kg/m³, project-reportedDensity
Five measurements show which stage holds the farm back.
A farm is limited by its weakest stage, not its tank volume. Before we design anything, we ask for these readings, taken at the worst time of day: two to three hours after the main feed.
Dissolved oxygen in the tank after feeding
Falls toward the level where growth suffers (for tilapia, below 3.5 mg/L)
Oxygen supply or transfer
Total ammonia and nitrite
Rise after feeding, or after feed is increased
Biofilter too small for the feed
Carbon dioxide or pH trend
CO₂ above the species limit (tilapia: 40 mg/L); pH falling over weeks
Degassing; alkalinity
Water clarity and settled solids
Cloudy water; solids settling around tank drains
Solids removal; tank hydraulics
Feed intake and growth
Fish stop eating before the feed plan says they should
One of the above
Limits quoted for tilapia from . We use the published limits for your species.SRAC Publication 282
Keep what still works.
Building
Kept
Floor levels, height, power and access
Tanks
Often kept, as in Riyadh
Shape, drains and inlets; whether solids reach the drain
Drain lines
Sometimes resized
Capacity for the new flow
Biofilter
Often too small for the new feed
Media volume against the new peak feed
Oxygen and degassing
Often missing or undersized
Capacity at peak feed
Pumps
Kept if they match the new flow and head
Duty point; standby
On tanks: round tanks clean themselves only with the right flow and drain layout. In dual-drain trials, solids settled around the centre drain at one tank exchange per hour (). An upgrade often fixes inlets and drains, not the tanks.NRAC project report 97-6
Survey, then rebuild.
1
Survey
Photos, drawings and current numbers: species, feed, flow, problems.
2
Diagnose
The five readings above show which stage limits the farm.
3
Layout
A new loop around your tanks, with a flow balance. First layout in 3 days.
4
Changeover
We plan installation with you to limit downtime.
Keep fish alive while the loop is rebuilt.
Section by section
The farm has separate loops or can be split; part keeps producing
Between batches
Harvest timing leaves tanks empty for a while
New loop beside the old
Space allows; switch over when the new biofilter is ready
Biofilter seeded ahead
Any approach: the new biofilter is started before fish depend on it
We diagnose before we sell.
Diagnosis first
We find the limiting stage before quoting.
Two upgrades delivered
Riyadh tilapia and Shaxian eel.
Single stage if that is all
We size one stage against the rest of your loop.
On site to start-up
Engineers stay until the new biofilter is running.
Upgrades we delivered.
Keep the tanks. Change the water.
Send photos and a site plan. We tell you what can be reused and what needs to change.
It depends on the layout. We plan the changeover with you to limit the time tanks are out of use.
Yes. If only the biofilter or oxygen limits you, we size that stage against the rest of your loop.
Oxygen, ammonia, nitrite and CO₂ or pH readings taken after feeding, plus feed per day, flow, tank sizes and photos.
It depends on what limits you now. In Riyadh, project-reported density rose from 20 to 50 kg/m³. We give an estimate after the diagnosis, not before.
Often, yes. Riyadh kept all 25. We check drains and inlets.
Send photos and numbers. We find what limits your farm.
Send species, target output and site size. A first layout comes back in 3 days, free.
- Survey of your existing system
- Layout around your tanks
- Flow balance for the new loop
- No obligation to order