The old circular guppy tank is actually a plastic kitchen basin/tub that had been under the sun for about 4 years now. Its upper surface is turning to powder and should be very fragile by now. What I'm worried about is the amount of plastic chemicals that had been leaching into the system for all these years. In fact, there is a strong plastic smell when I sniff the basin's rim.
|Plastic surface turning into powder... The effects of 4 years of sun damage...|
|White patches are 4 year old stains from adhesive paper tape... Those lighter colored scratch marks are my attempts at removing the tape... Scratching the surface releases a lot of dust particles and smell...|
And so, I decided to get them a new tank today. It's smaller than the growbed but much bigger than the previous circular tank. After adding the new tank to the system, I realized that quite a significant amount of water was drawn up to the new tank lowering the water depth in the tilapia tank. I worry that the shallower water will now cause the water to heat up quicker during noon. And so I proceeded to add 3 more pails (39 litres) of water salted to 3ppt into the system.
|This photo was taken at 8:15 pm. It was already pretty dark during that time, but the camera's flash made it seems like it was taken during noon.|
Just to be safe, I will conduct further water changes in the future to remove any more lingering chemicals in the system's water. I won't be consuming any vegetables (the mint, pegaga, and kangkong) that was planted or will be planted before completing the future water change in case they had absorbed some chemicals in them. I won't be culling my guppies and pleco as I won't be eating them, but they might continue pooping out plastic tainted poo for some time which may go in to my plants or find a way into tilapia blood stream. I will ignore those minute traces of plastic chemicals and only seek to minimize instead of a total removal. I'm sure I should be worrying more about other pollutants such as vehicle exhaust and cigarette smoke than plastic chemicals leaching in to water.
Thanks for reading...