Stored rain water.

[Gerry]

Hi everyone,
Had a discussion with some one today about possible water supply. Been in the city NY city water gets expensive if you use enough as you are charged for the waste treatment for what you use. So when it comes to aquaponics, I'm paying the city to treat water that is evaporating.
The question is can stored rain water be used if it came off a plastic sheathed roof with no metallic surfaces.
Does it need to be treated with UV light before you enter it into your system, or is there still a chance you can bring a virus into your system by using it.
I'm going to start researching this myself but anyone knowledgable on this subject I sure would appreciate a response.
Thanks Gerry

[Jonathan Kadish NYC AA Chair]

Hi Gerry,

I am in NYC as well. For this to be a concern then you must be planning a large system. From what I understand from previous discussions rain water can be a good source for AP but being in the city I would worry about particulate pollution from all the industry and transportation around. You can see it build up on building facades. Other than that issue rainwater is devoid of minerals that plants need in trace amounts, so you may need to add things like Iron, Calcium, potassium ect... You should also be aware that certain plastics that you would collect rain water with may leech contaminates especially when baked under the sun.  Keep in touch... I love to help locals make stuff happen!

[Gerry]

Hi Jonathan,
Thx for the reply. Is the pollutant problem from what the rain gathers as it falls or only what has gathered on surfaces and washes into the water. Could the mineral deficiency be made up with maxi crop and other supplements you have mentioned.
Is it possible for bacteria / viruses to migrate into the stored water that is harmful to the fish?
As for system design nothing planned yet. Still a lot of core study to complete before I even take short Aquaponic courses that are offered.


Jonathan Kadish NYC AA Chair said:

Hi Gerry,

I am in NYC as well. For this to be a concern then you must be planning a large system. From what I understand from previous discussions rain water can be a good source for AP but being in the city I would worry about particulate pollution from all the industry and transportation around. You can see it build up on building facades. Other than that issue rainwater is devoid of minerals that plants need in trace amounts, so you may need to add things like Iron, Calcium, potassium ect... You should also be aware that certain plastics that you would collect rain water with may leech contaminates especially when baked under the sun.  Keep in touch... I love to help locals make stuff happen!

[Jonathan Kadish NYC AA Chair]

I don't claim to be an expert in rainwater collection. You could always run a test collection sample and have it analyzed at a lab to see if it is safe, although I imagine they don't test for BPA or other compounds that might leach from plastic. As for bacteria you would need to run the water through a UV filter which will kill anything living, a commonly used practice for well water. As for minerals, your fish food should cover most of it and your plants will tell you what they need from various signs of deficiency.