Water Topic

[Giorgio]

We have a plant topic and fish topic I think we need a water topic as water is the most important part of what we do.
I'm collecting rain water to use in AP and gardening but I read is not safe to use especially from asphalt shingles and other treated roofing systems. Is anyone here using rainwater? and how to filter it simply and cheaply?
Mahalo

[TCLynx]

Yes there definitely is a lot that can be discussed about water.

Rain, well, city, they all have pros and cons.

Yes, asphalt shingles don't make for the best rain water collection. The shingles tend to grab and hold impurities and give them up to the water. I don't know that filtration really does all that well with hydrocarbons either. I collect some water from our asphalt shingle roof but we mainly use it for rinsing and washing non edible things.

I don't know that any surface is perfect for rain water collection though. For a fish system you have to be careful of many metals (zinc and galvanizing are definitely bad for fish and galvanized tanks for rain water collection are not very good sources of Aquaponic system water.)

Some things to take into account when thinking about rain water collection.
Roof surface (material leaching) or pH in the case of concrete or gravel covered roofs.
Cleaning. good rain water collection systems should allow the roof to rinse off before water starts being collected. This can help deal with problems of bird droppings/other animal droppings on the roof as well as dust.

Concrete tanks can affect pH but can still be functional.

Hopefully some one with more experience can expand more on my little bit as I'm not using rain water for much as we have good well water here.

[Richard Wyman]

Ever notice how the air smells so crisp and clean after a rain? You know all the bad stuff that was making the air dirty is now in that water as well as all the roof debris you mentioned.

[TCLynx]

LOL, I don't get to experience that often here since it tends to be so humid the rain doesn't quite have the drastic effect on the smell of the air. I was out in AZ not to long ago though and was very reminded by a sprinkling rain giving a strong hot pavement odor.

But yes, if you are in a zone with heavy pollution, rain water might not be all that clean above and beyond the dust and debris.

[Sylvia Bernstein]

Giorgio, I saw your suggestion for a forum category on Water Topics. You are right...it is a "duh"... Thanks for the suggestion!

[zero power]

Im using rain water but having hard time... getting lots of algae and dead fish...
I have put a dark screen over the tops and tanks are in green house.. I will try to cover the side and the top better... Not sure if is a mineral lack or what..the gold fish i was tesing it with did okay untill I added MaxiCrop and that stuff ruined everything..
killed all fish and made water real thick, I had to empty tanks and start over.

I collect the rain water by installing gutters on the green house.. no asphalt to worry about

[zero power]

What is the best water source... besides a well that is... should we use reverse osmosise with tap water? or reverse osmosise with rain water or just treat the tap water?

[Giorgio]

I collect rain water but haven't used it on my system yet, after doing some research and talking to some people I realized that before using the water it must be filtered properly.
My friend's fish also died after using rainwater directly. At this moment I'm working on a sand bio filter that can be built cheaply. This is what I'm doing: http://www.slowsandfilter.org/illustrations.html.
In the mean time I just use tap water and let it sit for at least 24 hrs before putting in system

[TCLynx]

Rain water is going to be soft and could also be acidic. If using rain water one will probably need to add some minerals to help harden the water up a bit, first on the list will be a bit of limestone to provide calcium and buffering. Depending on the type of lime used, extra magnesium might be needed too. Most fish like a certain amount of hardness and the bacteria needs a certain pH range to work well. If a system is started with minimal buffering material added and is using rain water, it is highly likely that the pH will drop as the system starts to cycle up and the process may halt and ammonia spike causing all sorts of problems.

Zero power, what was the pH of your system you were having problems with? Did you add any lime or shell grit? Rain water may be great but you do have to provide it with some buffering to make it work.

[zero power]

ph of 6 1/2.. I didnt add anything to it... Our tap water is so harsh here .. ph of over 9

TCLynx said:

Rain water is going to be soft and could also be acidic. If using rain water one will probably need to add some minerals to help harden the water up a bit, first on the list will be a bit of limestone to provide calcium and buffering. Depending on the type of lime used, extra magnesium might be needed too. Most fish like a certain amount of hardness and the bacteria needs a certain pH range to work well. If a system is started with minimal buffering material added and is using rain water, it is highly likely that the pH will drop as the system starts to cycle up and the process may halt and ammonia spike causing all sorts of problems.

Zero power, what was the pH of your system you were having problems with? Did you add any lime or shell grit? Rain water may be great but you do have to provide it with some buffering to make it work.

[zero power]

I use the same rain water on my inside tank and all is good.. I have origional gold fish in it that are still alive... I used a ph up to bring up the level and all has been fine since about june.. I refill it with rain water also as the water level goes down..

zero power said:

ph of 6 1/2.. I didnt add anything to it... Our tap water is so harsh here .. ph of over 9

TCLynx said:

Rain water is going to be soft and could also be acidic. If using rain water one will probably need to add some minerals to help harden the water up a bit, first on the list will be a bit of limestone to provide calcium and buffering. Depending on the type of lime used, extra magnesium might be needed too. Most fish like a certain amount of hardness and the bacteria needs a certain pH range to work well. If a system is started with minimal buffering material added and is using rain water, it is highly likely that the pH will drop as the system starts to cycle up and the process may halt and ammonia spike causing all sorts of problems.

Zero power, what was the pH of your system you were having problems with? Did you add any lime or shell grit? Rain water may be great but you do have to provide it with some buffering to make it work.

[zero power]

thats an interesting diagram of the sand filter.. I may try to make one... thank you

Giorgio said:

I collect rain water but haven't used it on my system yet, after doing some research and talking to some people I realized that before using the water it must be filtered properly.
My friend's fish also died after using rainwater directly. At this moment I'm working on a sand bio filter that can be built cheaply. This is what I'm doing: http://www.slowsandfilter.org/illustrations.html.
In the mean time I just use tap water and let it sit for at least 24 hrs before putting in system

[Sahib Punjabi]

Yes, I do use rainwater, but only in small amounts, say 50 gallons every month or so (depending upon rains). Given that my Koi pond is approximately 1,000 gallons, this amount has not so far (touch-wood just in case I jinx myself), caused any negative action. I do like the diagram of the "sand filter" shared by Giorgio and I will try to build one soon.

I came across an interesting filtration method today, one using "Coir". What a wonderful idea especially if you subsequently use some of the coir as part of your medium for seed starting. Does anyone else use this method of filtration?

http://www.kitsapsun.com/news/2010/sep/17/backyard-aquaponics-shows...

zero power said:

thats an interesting diagram of the sand filter.. I may try to make one... thank you

Giorgio said:

I collect rain water but haven't used it on my system yet, after doing some research and talking to some people I realized that before using the water it must be filtered properly.
My friend's fish also died after using rainwater directly. At this moment I'm working on a sand bio filter that can be built cheaply. This is what I'm doing: http://www.slowsandfilter.org/illustrations.html.
In the mean time I just use tap water and let it sit for at least 24 hrs before putting in system