Using RO/DI waste water in freshwater aquarium?

[Drfu]

So after all the research that i have done i decided to order cpdi90mf for my reef systems vs buying ro water, I'm really looking forward to getting it next week! The one question i have right now with it is this:

Can i use the waste water for my freshwater tank?

I have googled this and have read everything from "sure i do", to "no too much tds" and everywhere in the middle.

If the waste water has no chlorine, chloramine, ammonia, nitrites or nitrates in it just minerals should this not be good enough for a freshwater planted system?

Or am i totally wrong with this and the pre filters don't remove these and the amount of tds coming out of the membrane are way too high for the fish/plants? My freshwater system is just your standard variety of plants & community freshwater tropicals.

I have read that using the clean rodi water is no good for fw tanks as it has all of the good minerals, trace elements and you would have to buy a bunch of supplements to make it safe. If this were the case i would just stick to using tap water & Prime.

Everyones thoughts on this would be great, thx in advance!

[neoh]

So, what's the difference between the RODI waste water and tap water? You should be dosing your macro and micro ferts with planted tanks (Kno3, Po4, etc.) (See: http://www.aquaticplantcentral.com/f...ing-guide.html) anyways, regardless of method.

Whats the TDS out of the tap? What's the TDS out of the rodi waste water?

I wouldn't see it as a problem. I had high tech planted tanks for years, and I would do it if I had both. It's still filtered through your carbon and sediment filters, so it would be much better than straight tap water, as tap water still has chloramine/chlorine in it for the most part.

I would make a batch of water from the waste water, use your prime with it, then dose your KN03, KH2P04, and trace elements in it before your water change.

However; I would do a test beforehand. I've had fish in waste water before (feeder goldfish) with no problem, so it doesn't strip needed elements from water.

Best of luck!

[michaelis88]

following this thread!

[AquaPin]

I have my waste water running outside to a 55GL drum that I use to top off the pond. Never had any issues, fish plants all seem fine.

[Drfu]

Originally Posted by michaelis88

following this thread!

Thread please

[Drfu]

Originally Posted by neoh

So, what's the difference between the RODI waste water and tap water? You should be dosing your macro and micro ferts with planted tanks (Kno3, Po4, etc.) (See: http://www.aquaticplantcentral.com/f...ing-guide.html) anyways, regardless of method.

Whats the TDS out of the tap? What's the TDS out of the rodi waste water?

I wouldn't see it as a problem. I had high tech planted tanks for years, and I would do it if I had both. It's still filtered through your carbon and sediment filters, so it would be much better than straight tap water, as tap water still has chloramine/chlorine in it for the most part.

I would make a batch of water from the waste water, use your prime with it, then dose your KN03, KH2P04, and trace elements in it before your water change.

However; I would do a test beforehand. I've had fish in waste water before (feeder goldfish) with no problem, so it doesn't strip needed elements from water.

Best of luck!

I will test tds of my tap water & ro water after i get the u it and installed them.

I dont dose my fw tank with anything but flourish excel once a week for my olants, what other trace elements should i be dosing a fw aquarium?

[StirCrazy]

it depends on the fresh water tank type you are running and what the extra dissolved solids in your water are. personally I wouldn't. I tend to favor soft water tanks, so I use the RO water for my fresh water tanks also.

the most important thing is to know whats in your original water source and what you are concentrating.

Steve

[Drfu]

Originally Posted by StirCrazy

it depends on the fresh water tank type you are running and what the extra dissolved solids in your water are. personally I wouldn't. I tend to favor soft water tanks, so I use the RO water for my fresh water tanks also.

the most important thing is to know whats in your original water source and what you are concentrating.

Steve

So if you are using ro water for your fw tanks, what supplements are you adding to make the chem correct for fw, ie trace elements, ph? If this is the case what benefits are their using ro vs conditioned tap water? It could be more work using ro vs conditioned tap water?

My tank has tetras, corys, otos, clown loaches & of course a bunch of plants. Right now all i do is use prime & tap, let it sit for day before using and add a capful of flourish excel.

[mike31154]

I have no experience with freshwater aquariums, but I would surmise that the benefits of using RO water are the same for both salt & freshwater systems. With RO you are starting with a "known" water quality, that is, there are no "unknown" impurities or dissolved solids in the water you are about to use.

Most likely you can use the waste water from your RO system for your freshwater tank no problem, after all, it does originate from a source that's safe for human consumption. But without a city water report that shows what's in your tap water, you really have no idea what you're adding, in what concentration and/or what you need to dose to correct the levels of whatever you consider desirable for your freshwater tank. Keep in mind that the RO waste water is a more concentrated soup of whatever comes out of your tap, with some sediment & the chlorine removed. Even with a city water report, the report is only a snapshot & water quality can vary considerably depending on the season & what the city uses as a source. You'd need a pretty comprehensive kit or home laboratory to test for all those minerals & impurities yourself.

Below are two water reports from my provider, the City of Vernon. We have multiple water sources & there are occasions when they switch supplies to various customers due to spring run off, turbidity, water quality issues etc. Reports show Kalamalka Lake source which supplies most of the water & the Duteau Creek source which they recently spent millions on to improve quality. Duteau Creek is much softer water. 99% of the time, I am on the Kal Lake source & my TDS reading out of the tap these days is fairly consistent between 165-170.

North Kalamalka Lake Intake Water Quality 2008
Water System: Greater Vernon Water
Source: Kalamalka Lake
Facility: Kal Lake Pumpstation
Sampling Point: Kal Lake Intake
Date: 7/14/2008

INORGANIC Results (mg/L unless noted)
Aluminum <0.050
Antimony <0.0030
Arsenic <0.0050
Barium 0.027
Boron 0.021
Cadmium <0.00010
Calcium 40.6
Chloride 5.38
Chromium <0.015
Copper <0.0030
Cyanide < 0.01
Fluoride 0.24
Iron <0.20
Lead <0.001
Magnesium 19.8
Manganese <0.0050
Mercury <0.00030
Molybdenum 0.005
Nitrate (as N) 0.069
Nitrite (as N) <0.010
Potassium 5.07
Selenium <0.0050
Sodium 18.4
Sulphate 51
Uranium 0.003
Zinc 0.011

PHYSICAL Results (mg/L unless noted)
Alkalinity (as CaCO3) 152
Colour <5 TCU
Conductivity 409 microS/cm
Hardness (as CaCO3) 183
pH 7.8
Total dissolved solids 238
Turbidity 1.0 NTU

Water System:Greater Vernon Water,
Source: Duteau Creek
Facility:Headgates
Sampling Point:Headgates Cl2 bldg (1-1-SR, 5E8D)
Date of Sample:7/19/2011

INORGANIC, Results (mg/L unless noted)
Aluminum (total) 0.114
Antimony (total) <0.0010
Arsenic (total) <0.0050
Barium (total) <0.050
Boron (total) <0.040
Cadmium (total) <0.00010
Calcium (total) <5.0
Chloride 0.21
Chromium (total) <0.0050
Copper (total) 0.0245
Cyanide (total) <0.01
Fluoride 0.13
Iron (total) 0.31
Lead (total) <0.0010
Magnesium (total) 1.23
Manganese (total) 0.02
Mercury (total) <0.00020
Molybdenum (total) <0.0010
Nitrate (as N) 0.02
Nitrite (as N) <0.01
Potassium (total) 0.8
Selenium (total) <0.0050
Sodium (total) 1.36
Sulphate 3.1
Uranium (total) <0.00020
Zinc (total) <0.040

PHYSICAL, Results (mg/L unless noted)
Alkalinity (Total, as CaCO3) 14.3
Colour 75
Conductivity 38 microS/cm
Hardness (total, as CaCO3) <12.9
pH 7.14
Total dissolved solids/TDS 44
Turbidity 0.9

There are plenty of other uses for RO system waste water. Some folks use it to fill their washing machine, but to me that's pretty hard water & I'd rather not have that stuff filtering through my textiles. I use it in the garden & to flush toilets. Been considering a 'grey' water system in my house to lower the water bills. I could plumb the RO waste into that. The way things are going with rate hikes around here, if I don't do something, I may even need to give up the hobby, along with my garden.

[mark]

guess the one advantage of using the RO waste is it's already stripped of the chlorine or chlromine through the carbon blocks, never liked the idea of Prime.