Lemon Grass is a hardy plant, well grass actually its able to grow in horrid condition and tolerate low fertility and low moisture content soil.
In order for it to grow in these condition, lemon grass has a very active root system and its very much intrusive most of the time. In Aquaponics where we have siphon, intrusive rooting plants or grass is a nightmare to upkeep.
I would recommend if you want to try Lemon Grass, plant it as far as possible from the siphon and its best to have it on a large growbed.
So in short it has to go.
I tried Lemon Grass to see whether they can be grown in Aquaponics. They thrive very well thank you, however the size of their bush and value to the kitchen don't justified this grass to be grown in Aquaponics. Due to my acute limitation of growing space I need to keep only those plant that will give maximum yield or usefulness to my setup.
Lemon grass and Okra removed from this bed, that Pandan is next. I will need to trim this Pandan to its minimum. Below what's left of Okra plant.
Pandan and Lemon grass in bucket of water, I will give these away.
Once all unwanted plants removed the dirty job starts. Roots matter need to be remove and how else to be done. Hand pick is still the preferred method.
This is the dirty job part of Aquaponics, those Lemon Grass sure have lots of roots. Plants like Okra is easy, pulled them out and most of the roots follow.
That growbed in the far end also need a minor redo, I do that next month. We can't do all growbed at once its bad for the system balance, you may get Ammonia spike and problem to the fish.
Its not as bad as it looks.
Once all rooting matter out , I redo this growbed. I am trying out using brick arranged vertically to form a hexagon cage around the siphon. Hexagon shape arrangement make the brick able to support growbed material around it.
Below at high water level. This growbed is about 1 brick length high about 7.5 inches, its not optimum for growbed. Its best to have it like 12 inches, however I am using pebbles for growth media its going to be very heavy if I make it 12 inches. A compromise at about 8 inches so far so good.
Below siphon at lowest water level. The strainer pipe is not needed with this arrangement but I decide to just leave it there and see how its goes.
I like to make things as flexible as possible so that we could expand as and when required, so if I need to increase the growbed heigh to 12 inches I just need to put few brick on top of existing, lengthen the siphon standpipe and add more pebbles.
A circular open ended porcelain or clay cylinders also will do the job. I will try to look for something like that next time I do the siphon.
Its about time that I redo the water feed, so 20mm pvc feeding water to growbed on two sides, and below is my make shift water flow indicator.
I will try Cherry Tomato on this bed, I already sown theirs seed three days ago.
Update : 19th Sept
I covered the hexagon cage with pot tray so that algae do not grow within the cage.