# recycling water



## david f (Mar 24, 2006)

Hello there folks,

I have been thinking lately how I can reuse my used aquarium water by means of using activated carbon to purify the water in a storage drum until it's suitable to be used again in the aquarium. Is this a possibilty,or are there any other sugesstions you may have to offer?

Cheers David f.


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## imeridian (Jan 17, 2007)

RO system with a pump?

I'd much rather use the water in the garden and for houseplants than try to clean it up for reuse in the aquarium.


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## david f (Mar 24, 2006)

To indiboi.

Thanks for your reply.I appreciate the garden like's the water and that using fresh clean water is the way.but I find it interesting to recycle if possble. using a filter could work a powerful pump used to push the water through, dirty filters? .

Cheers David f.


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## Fortuna Wolf (Feb 3, 2007)

To remove organics you can use activated carbon, but it works best with organics that have aromatic rings or, IIRC, longer carbon chains. 

But it won't remove salts and other strongly polar compounds, like sugars and alcohols. 

Probably the only ways to actually purify the water would be either distillation or RO. 

I'd stick with trying to maintain the nutrients at optimal levels while having enough plants/algae to absorb excess soluble waste. Though eventually long chain organics like tannic and humic acids will build up that plants, algae, or bacteria won't break down. But then you change the water when it starts to look too yellow and is absorbing too much light.

PS: you can't mechanically filter or chemically filter clean the water of all dissolved organic or salt compounds. You need to biologically absorb as much of those and then remove them (in the form of plants and algae and detritius), or remove the water from the impurities (distillation or RO).


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## imeridian (Jan 17, 2007)

Some RO systems use a booster pump to help increase water pressure, I don't know if that would work in this situation though, not really sure of the specifics.

I change 50% of my 75 gallon aquarium water every week, that's less than just taking an average shower, so I really don't worry about it. I reuse it wherever I can for plants, but if it just goes down the drain so be it. 

When it comes to saving water I think it'd be better (more cost efficient and effective) to look somewhere else. Compared to washing machines, dishwashers, showering, toilet use... the aquarium water use is quite minimal.

Just my two cents as they say... look into a low-flow shower head if you don't use one, it'll probably save you far more water.


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## david f (Mar 24, 2006)

thanks indiboi, yes when I look at it that way I do agree with you ,but just seems to be quite a lot of water to go through. Regards to Fortuna Wolf, It can be done ,thanks for the intresting information on the subject ,I will look into finding out a little more about this.I do think distillation could be an intersting approach.

thanks .david f


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## david f (Mar 24, 2006)

O.k. ,using activated carbon to remove organic's and then remove any biological impurities sounds very clean, as for salts RO filteration and a suitable pump would be the finished product.


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## hoppycalif (Apr 7, 2005)

Distillation requires energy, and energy is normally available only as electricity, and electricity is a major generator of excess CO2 in the atmosphere, causing increased global warming. In fact, almost any process which will clean that water will also require a lot of energy, making the water savings be offset by excessive energy use. Think of it like driving 100 miles to buy plants cheaper - not a good trade-off.


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## Diana K (Dec 20, 2007)

For me the optimum in this direction is:
Something closer to the NPT, but I do need to do just enough dosing for the plants to not show deficiencies, not enough to get into the EI method that calls for bigger water changes. 
Then reduced water changes.
Followed by irrigating my fruit trees with the water change water.


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## praxis5624 (Apr 22, 2006)

The recycling principle is a good concept but the cost ratio isn't wise. You will spend more purifying than just recovering this water for your yard/garden that would benefit most of the time from the residuals you seek to remove. I have recycled water for years, pumped it from my tanks and pond to my garden where I grew vegetables at an amazing rate. Just an idea.....


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## HTN86 (Nov 2, 2007)

Even if you come up with a method to do so, it's still cheaper to just change the water. If it was cheaper, I'm sure the majority of the people would be doing this already.


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## newbie314 (Mar 2, 2007)

Solar still 



hoppycalif said:


> Distillation requires energy, and energy is normally available only as electricity, and electricity is a major generator of excess CO2 in the atmosphere, causing increased global warming. In fact, almost any process which will clean that water will also require a lot of energy, making the water savings be offset by excessive energy use. Think of it like driving 100 miles to buy plants cheaper - not a good trade-off.


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## Hashbaz (Apr 23, 2006)

RO systems waste a lot of water. Mine spits out roughly 10 parts "waste" water for every part "pure" water. They do this to keep the RO membrane clean so that it will last longer. But I'm not sure if they all work this way.

As others said, purifying your water to be reused in your aquarium is not effort/cost effective.

What are your reasons for wanting to recycle the water? Cost saving? Water saving? Effort saving? Novelty?

If you are just trying so save water, you could plumb the aquarium to fill up a toilet. Personally, I like the idea of using aquarium water to water the lawn or garden.


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## kitfoxdrvr (Dec 29, 2007)

This has been a discussion on a larger scale at several of the koi and pond forums. One way with promise is to oxidize the contaminants in your "used" water with potassium permangate, which eliminates most organic compounds, but presents its own hazards if used incorrectly (it is a nasty chemical if used improperly and can be FATAL to all flora and fauna). Go over to www.koiphen.com and search "roddy conrad PP" and you will get lots of hits to read. You still have the question of what is "used up" in the water and the concentration of salts over time due to evaporation. Good question and very thought provoking, though!

Steve


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## neilfishguy (Mar 10, 2008)

I agree RO is not going to save much water unless you plumb the return back into your pipes, and you dont want to do that with dirty water...


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## Fortuna Wolf (Feb 3, 2007)

actually, i bet that a UV sterilizer will also be able to remove a lot of the organics - a straight oxidizer like sodium hypochlorite, potassium permaganate, or ozone would work best, but you don't want to inline those into your tank. 

Plants will take up a lot of salts (but not really sodium or chloride...)...


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## modster (Jun 16, 2007)

hoppycalif said:


> Distillation requires energy, and energy is normally available only as electricity, and electricity is a major generator of excess CO2 in the atmosphere, causing increased global warming. In fact, almost any process which will clean that water will also require a lot of energy, making the water savings be offset by excessive energy use. Think of it like driving 100 miles to buy plants cheaper - not a good trade-off.


i total agree with hoppy here. I think the best use of dirty water is to flush toilet....


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