Fish loss

1. In the event of death

Remove dead fish immediately.
The ammonia level may rise. Test your ammonia level and stop feeding your fish until the level goes back down.

Remove sick fish quickly.
We recommend quarantining sick fish in a separate tank equipped with a very good filter. You can ask your local aquarium store how to help them recover.

[TODO - Recommendation on care for fish]

2. Probable causes

Cause 1: ammonia spikes

Remember that ammonia is lethal for fish, and when the water pH is high (7+), you increase the conversion of ammonium into ammonia, which is more toxic to fish than ammonium. Ammonia is also more toxic at higher temperatures. Ammonia spikes can be caused by a drop in the microbial population or if you have just removed many ZipGrow tower units from the system. Do not forget to put them back quickly into the system so that our microbe friends can get back to work.

When you are in the red zone (high pH + high temperature), your fish is more likely to be poisoned by ammonia. This scenario is likely when you add fish to a non-cycled system in the middle of summer.

Cause 2: too much food in the fish tank

A fairly common cause is having given too much food in the fish tank compared with what the fish are able to consume. As a result, excess food will rot in the water, clog the filter and create a phosphate spike. You can confirm this problem if the water becomes saturated with particles, if the filter is excessively clogged and if you measure excess phosphate (specific test to be carried out).

Cause 3: sudden drop in pH

See The impact of pH on crops

Cause 4: unsuitable temperature

A sudden change in temperature or a temperature that is not optimal for the type of fish can cause death. Remember to respect the ideal temperature ranges for fish.

Cause 5: water change that is too sudden

When you add an external water source to the fish tanks (rain, well), always pay attention to the temperature and pH of this water to avoid shocking the fish. It is recommended to change/top up a maximum of 10% of the water per day.

Cause 6: overcrowded fish tanks

An overcrowded fish tank can cause fish health problems. You can therefore eat some of them.

Cause 7: diseases

If you filled the fish tank with stagnant rainwater or brought sick fish into the system, your fish may be contaminated. Identify fish with spots and quarantine them.

Cause 8: not having waited until the end of the cycling period

Remember that the system is only cycled when you measure nitrates and have very little nitrite and ammonia in the water.

Cause 9: low KH

In aquaponics, it is recommended to stabilise the KH, carbonate hardness, around 4-5°d. This parameter is important and determines the stability of pH over time. A hardness below 4°d could affect fish wellbeing and lead to mortality.

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Tips
To avoid ammonia spikes, pay close attention to:

Not overfeeding your fish

Not leaving dead fish in the fish tank

Not leaving food remains to rot or solid particles in the fish tank

Avoiding a pH level above 8.5

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Improving filtration with pozzolan
To improve water filtration, you may consider adding a floating mesh bag of pozzolan to the water. Pozzolan is a porous rock intended to capture excess minerals in water. It provides additional support for beneficial bacteria in the water.