RO/DI waste water, can it be used for a fw aquarium?

[drfu]

So after all the research that i have done i decided to order the Spectrapure 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!

[AZDesertRat]

The waste has only been through a sediment filter to remove big floaties and a carbon block to remove chlorine. You have done nothing to remove nitrates, nitrites, ammonia or anything else. The TDS will be 20-25% higher than the tap water was at 4:1 waste ratio and 33% to 50% higher at 3:1 or 2:1 waste ratio. Unless you are using softened water and have lower than normal TDS then stick with the 4:1 waste ratio and if your tap water is safe to begin with then the 20-25% higher TtDS won't be a big issue for freshwater fish, especially brackish fish.

[drfu]

The waste has only been through a sediment filter to remove big floaties and a carbon block to remove chlorine. You have done nothing to remove nitrates, nitrites, ammonia or anything else. The TDS will be 20-25% higher than the tap water was at 4:1 waste ratio and 33% to 50% higher at 3:1 or 2:1 waste ratio. Unless you are using softened water and have lower than normal TDS then stick with the 4:1 waste ratio and if your tap water is safe to begin with then the 20-25% higher TtDS won't be a big issue for freshwater fish, especially brackish fish.

The SpectraPure system i got is a 2:1 system but i installed the 3:1'hose instead so that the filters/ membranes last longer. It came with some test strips to check hardness & my tap water is somewhere between 50-120gph or 3-7 dh. The waste water measures between 425-1000gph or 25-59 dh but i hate color tests, and strips are even worse imo so i think these are more like guesses!

 

I guess my next purchase is a tds meter and a gph test kit befor trying out any waste water on my fw tank would be wise, more $ and more test kits, lol!

 

Im assuming that i don't need prime on waste water as all it does is remove chlorine & chloramine and i also leave my water out for 24 hours before use anyways, is this correct?

[AZDesertRat]

The carbon block will have removed the chlorine. If your water is treated with chloramines though it will still contain ammonia as the DI resin is where the ammonia portion of chloramines is removed. Prime will bind the ammonia so it is not as toxic but it is still there and has not been removed.

 

It is almost impossible to own a RO/DI without having a good handheld TDS meter to monitor its performance. Your test strips test the grains per gallon (GPG not gph or gallons per hour) hardness but that only tells part of the story and not even a big part since hardness is generally made up of only two things, calcium and magnesium, its the others that are the problem.

[drfu]

The carbon block will have removed the chlorine. If your water is treated with chloramines though it will still contain ammonia as the DI resin is where the ammonia portion of chloramines is removed. Prime will bind the ammonia so it is not as toxic but it is still there and has not been removed. It is almost impossible to own a RO/DI without having a good handheld TDS meter to monitor its performance. Your test strips test the grains per gallon (GPG not gph or gallons per hour) hardness but that only tells part of the story and not even a big part since hardness is generally made up of only two things, calcium and magnesium, its the others that are the problem.

So i have tested my waste water with my @&$%# API freshwater test kits & here are the results:TDS 220 (tap water was 200)Ph 7.4 - 7-8Kh 7dKh or 126 ppmAmmonia could be as high as .25 ppm but i can not tell for sure??Phosphates .25 ppmCopper, nitrites, nitrates are not detectableI am thinking this should be more than safe for a freshwater aquarium considering i have been using conditioned tap water for some time w/ no issues.

 

The waste has only been through a sediment filter to remove big floaties and a carbon block to remove chlorine. You have done nothing to remove nitrates, nitrites, ammonia or anything else. The TDS will be 20-25% higher than the tap water was at 4:1 waste ratio and 33% to 50% higher at 3:1 or 2:1 waste ratio. Unless you are using softened water and have lower than normal TDS then stick with the 4:1 waste ratio and if your tap water is safe to begin with then the 20-25% higher TtDS won't be a big issue for freshwater fish, especially brackish fish.

Got myself a tds meter today, my waste water reads @ only 220, my tap reads 200 & my tank w/ everything in it reads 247 so I'm thinking waste water should be fine

[AZDesertRat]

Your waste ratio is too high and you are wasting water down the drain. The waste TDS should be 240 to 250 if the system is dialed in properly which would provide more pressure to your RO membrane and help the rejection rate or removal efficiency.

 

Do you have a water softener? If so you could reduce that waste ratio even a little further and help the RO more still. This would raise your waste TDS to around 300 but make your RO more efficient at the same time.

 

What do you mean by your tank with everything in it reads 247? What tank and what everything?

[drfu]

Your waste ratio is too high and you are wasting water down the drain. The waste TDS should be 240 to 250 if the system is dialed in properly which would provide more pressure to your RO membrane and help the rejection rate or removal efficiency.

 

Do you have a water softener? If so you could reduce that waste ratio even a little further and help the RO more still. This would raise your waste TDS to around 300 but make your RO more efficient at the same time.

 

What do you mean by your tank with everything in it reads 247? What tank and what everything?

 

I went with the 3-:1 ratio vs the installed 2:1 as i was told by SpectraPure as our water up here is hard ( i just tested my ro waste water, it was @ 10 dGh). Im not too concerned with the amount of waste water i produce & my water pressure is 80psi which the manual says is max i should run ( installed a valve to knock it down or i would be running over 100).

 

I own a condo and i do not believe we have a water softener & my unit only has a 2:1 & 3:1 options for waste water control. Again the amount of waste water isn't a big deal to me as my final water quality & my filters/membrane lasting.

 

The 247 tds reading was my fw aquarium water as i wanted to know what my tank water has been @ all these years & since i have never owned a tds meter before i was curious to know and maybe use it as a baseline reading.

 

So now from my tests that i have done on my waste water my feeling is its fine to use in my fw aquarium, right? Or wrong? And should i use a combo of final water & waste or is waste just fine with these results?

 

Since Prime just binds and does not remove anything should i use it at all since we don't have chloramines in our water up here or do i use it just in case the city starts to?

[AZDesertRat]

Have you actually used a measuring cup and timed your wate ratio? It does not sound like the ratio is what you think it is if the waste TDS is only 220 and a tap of 200, it should be 240-250 at 4:1 and around 300 waste at 3:1.

 

Higher pressure is a good thing, I run 95-100 psi on purpose to improve my rejection rate to 99.4%. Membranes love pressure and are rated at 150 psi +, it is the off brand imported housings some ebay vendors use that are the weak point.

 

247 seems very low for an aquarium, fresh or otherwise. I would think the meter would be out of range at over 999 due to the wastes and accumulated solids over time from evaporation.

[jblank44]

I would risk it, that is all the bad stuff coming out of your tap

[drfu]

Have you actually used a measuring cup and timed your wate ratio? It does not sound like the ratio is what you think it is if the waste TDS is only 220 and a tap of 200, it should be 240-250 at 4:1 and around 300 waste at 3:1. Higher pressure is a good thing, I run 95-100 psi on purpose to improve my rejection rate to 99.4%. Membranes love pressure and are rated at 150 psi +, it is the off brand imported housings some ebay vendors use that are the weak point. 247 seems very low for an aquarium, fresh or otherwise. I would think the meter would be out of range at over 999 due to the wastes and accumulated solids over time from evaporation.

I have a 5 gallon bucket for final water and used a 5 gallin jug for my waste water to see how much i woulf get, when the 5g waste water jug was full i had about 2 gallons of goo, didnt do any actual measuring.I will crank up my tap and see what kind of psi i get.I dont know how accurate HM is for a tds meter, only cost me $25.I did a wc today usi g 5 gallons of rodi & 5 gallons of waste water, will post chemestry results before & 24 hours after tomorrow for comparisons.

 

I would risk it, that is all the bad stuff coming out of your tap

We shall see tomorrow with what my test show not that i have a gh test