Aska's Aquaponics: System Update

It has been 9 days since my last update...
This is a photo taken on 25th April:

I accidentally broke that kangkong... :-(

and here's a photo taken today:

That broken kangkong raised up, fell the other way, and raised up again...

Notice that I had added more clayballs into the growbed... I used Hydro-Korrels:

And now some closer pictures to show the size of the plants:

Look how big this kangkong is!

The largest okra in the growbed...

Mint leaves are two times larger than when I first bought them from the market!

I also have problems with pests:

Miner inside okra leaf

Dead leaf miner... I squished it while still inside the leaf... XD

Adult leaf miner...

Kangkong leaf eaten by a beetle

Here's the shiny little guy...

Other than bugs, I also have problems with foliage damage caused by falling fruits from the tree branches above...

These pink fruits may be tiny, but they are quite hard. When they fall from 20 feet above, they hit hard! One fell on my head once...

Finally, the fish...
After several more fish deaths, I checked the pH and it was 6.0...
Ammonia was at 0.5, Nitrite at 0... I'm not sure what is causing the tilapias to die... Could it be the pH?? But I thought tilapias are very resistant...
So I refered to an aquaponics proverb:

"When in doubt, do a water change"

and that's what I did...
I removed 100 litres of water, and added new water till the tank is almost full... I also added back the corals to buffer the pH...

Since then, no more deaths!