Sure this has been asked before: RO vs rain water?

[jkratzwald]

I live in an area that does NOT have good water for discus. Tap PH is about 8 and hardness is at or above 300.

I'm just now starting to set up for discus and found some 2.5 juvies that I REALLY want. However, I don't have an RO system yet and can't afford the juvies and RO system at the same time.

As an experiment, I tested some rain water that has aged a bit. Hardness was basically zero and PH was a little under 7. I have the capability of capturing and storing large amounts of rain water. Would this be suitable when I find the right mix of rain and tap water to create good discus water until I can get a good RO system?

On a side note: How important are the water parameters for a grow out? I know that I want to breed and the water has to be at certain conditions, but does that apply to a grow out or is massive water changes the only key for the grow out?

Thanks in advance

[rickztahone]

You can raise discus with your tap water, no problem. Does your pH show any type of swing after 24hrs?

[jkratzwald]

No, there isn't much of a swing, maybe a couple of 10ths at the most. The hardness is my concern. As I'd said, I know hardness comes into play for breeding, but didn't know if it is much of a factor in growing out.

I do know that the place I want to get the juvies from keeps very discus friendly water. PH is right at 7 and the hardness is around 120.

[jkratzwald]

Just to add: I do age my water for a day before change out now in my angel tank. Our water is very heavy on chlorine. The main tank is a 90 gallon. The aging tank is about a 30 gallon. I fill it with tap, use prime, aerate for at least a day then pump it into big tank. Big tank has an overflow with drain to sump pump, so as the new water is pumped in the out going water goes straight to the sump pump. I plan on doing the same with the discus grow out tank. The grow out tank is a 45 gallon and I want to start with the 4 juvies, then add 4 more as money allows.;)

[rickztahone]

Just to add: I do age my water for a day before change out now in my angel tank. Our water is very heavy on chlorine. The main tank is a 90 gallon. The aging tank is about a 30 gallon. I fill it with tap, use prime, aerate for at least a day then pump it into big tank. Big tank has an overflow with drain to sump pump, so as the new water is pumped in the out going water goes straight to the sump pump. I plan on doing the same with the discus grow out tank. The grow out tank is a 45 gallon and I want to start with the 4 juvies, then add 4 more as money allows.;)

Do you have another aging barrel though? The 45 will work for a while whilst you grow them out, but they will need to move soon. Your tap water will be fine though, especially since you age. Use prime/SAFE and you will be fine.

[briztoon]

I use a mix of rain water and tap water. I run both through a two stage, 0.2 micron and carbon filter in to an IBC for ageing.

[Jack L]

i raised Ds in tap water of pH of 8.4 w/o any problem.

tip: check you tap water for nitrates.

[John_Nicholson]

Tap water is fine. In fact they will grow better in hard water. The trouble with rain water is you can never really be sure what is in it.

-john

[Jack L]

Tap water is fine. In fact they will grow better in hard water. The trouble with rain water is you can never really be sure what is in it.

-john

John, are you referring to gh or kh? I guess I didn't realize they grow better in hard. I add back to RO so if GH I can just put in more seachem equilibrium.

[Skip]

John, are you referring to gh or kh? I guess I didn't realize they grow better in hard. I add back to RO so if GH I can just put in more seachem equilibrium.

LOL> john don't measure water.. other then the gallons to fill tanks up!! LOL>.

kiss it simple.. tap is fine

[John_Nicholson]

Tough questions....LOL. There are lots of things that are in water. Basically when something is growing they need different minerals and such. Hard water generally has more of that stuff. Softer water can be fine or it could be missing some of the stuff. Back at least 15 years ago I was talking to Jack Wattley while he was at one of out local shows. He mentioned that if he had a spawn that we want to grow out that he would keep half and give half to a friend. That friend had hard well water and that half of the spawn would always out grow the half that he kept. It got me thinking...that was the day I started using my ro waste water for my growout tanks.

-john

[Jack L]

LOL> john don't measure water.. other then the gallons to fill tanks up!! LOL>.

kiss it simple.. tap is fine

Well my tap has 40 plus nitrate....

[John_Nicholson]

Well my tap has 40 plus nitrate....

That sucks....LOL.

-john

[briztoon]

"Pure" rain water should be pH7 neutral. However as rain water falls it absorbs pollutants from the atmosphere. Depending where you live, depends on how much pollutants are in the atmosphere. This is what causes acidic rain, so pH lower than 7. Once the rain hits your roof, it picks up material from your roof, typically bird and bat droppings, and any plant matter from. Just look in your gutters, and this is what rain water will be running through. Imagine the bacteria growing there.

[DJW]

I have an aluminum roof, and besides it doesn't rain anymore in California anyway.

The well water here is also 45ppm nitrates... and that definitely sucks.

[rickztahone]

Well my tap has 40 plus nitrate....


That sucks....LOL.

-john


I have an aluminum roof, and besides it doesn't rain anymore in California anyway.

The well water here is also 45ppm nitrates... and that definitely sucks.

I will pledge my vote and agree with all of you, that sure does suck ;)

[Jack L]

Tough questions....LOL. There are lots of things that are in water. Basically when something is growing they need different minerals and such. Hard water generally has more of that stuff. Softer water can be fine or it could be missing some of the stuff. Back at least 15 years ago I was talking to Jack Wattley while he was at one of out local shows. He mentioned that if he had a spawn that we want to grow out that he would keep half and give half to a friend. That friend had hard well water and that half of the spawn would always out grow the half that he kept. It got me thinking...that was the day I started using my ro waste water for my growout tanks.

-john

have you ever recreated his "experiment"
raise 1/2 your batch in the RO waste, and the other 1/2 in regular water and see if you notice difference.

[Woodduck]

Florida rainwater good. um um

[Hart24601]

Just FYI the national enforceable legal limit for tap water is 10ppm nitrate. Unless someone is on non-public water you might not want to trust your test kits if your getting over 10ppm from the tap as that isn't legal and their test systems are far beyond what most people can afford. Here in Iowa we have real issues with nitrate in the tap and they have to run expensive systems to get the tap below 10. Not sure about different areas but our water works shows the nitrate of our source water. Of course if not using public water all bets are off and it's probably good to have a professional test since high nitrates is pretty bad for young children.

http://water.epa.gov/drink/contaminants/index.cfm

http://www.dmww.com/water-quality/water-quality-data/

[Jack L]

Mine is municipal, their report for 2014 said 7.6ppm

If both the seachem and api kits read high...
But I have repeatedly read comments about hobby kits being inaccurate. Makes me wonder what the right answer is. Are these kits any good at all?

[TexMoHoosier]

"Pure" rain water should be pH7 neutral. However as rain water falls it absorbs pollutants from the atmosphere. Depending where you live, depends on how much pollutants are in the atmosphere. This is what causes acidic rain, so pH lower than 7. Once the rain hits your roof, it picks up material from your roof, typically bird and bat droppings, and any plant matter from. Just look in your gutters, and this is what rain water will be running through. Imagine the bacteria growing there.

In theory, pure water (rain, RO, distilled, etc.) will have a pH of 7, but pure water is a poor buffer, so don't panic if you use an RO purifier and see your pH drop well below 7. Atmospheric CO2 will dissolve in the water some converting to HCO3- and a H+. That increase in H+ is what drives the pH down. So just because you see the pH of your water drop, it does not mean there are pollutants in it. On the flip side, pollutants (heavy metals, bird feces/bacteria, etc.) that rain water may pick up while running off a roof or other surface will have no effect on pH.

[wcav]

I used to keep Angels in city water treated with prime and aged .I had no RO system.They always died .No mater what size and zero nitrates etc.Then I remembered that in the tropics as a kid we kept our fish in rain water with no issues.So I started collecting rain water.What I did was filter it.Age it and then switched out the water in phases.The angels stopped dying and spawned.This is in Florida rain water.I was not interested in angel babies.I had Africans in City water and they had lots of babies.No issue.Just too aggressive. I found out about Discus from the LFS.I converted to Simply D.I use Rain water and filter the city water through peat for at least a week to lower the PH. We have hard water with high PH from the city.I mix both but check on the parameters carefully.I am not growing out any babies.My Domestics have spawned but I keep them separated.I do not have the space or time to do breeding.I will one day with the Wilds.Just have to find more space ...juggle thing around....:o..In the tropics rain water was safer to drink than City water,here in Florida we still have to monitor the quality.What I found out is that any rain water from the Gulf is PH 7.1 and from over land i.e. from the East is acidic 5.3 to 6.5 PH depending on the time of year.I am in the Tampa Bay area.I do notice a big response with the Wilds when ever I add rain water the just swim up to it.The tap water they are indifferent.

[nc0gnet0]

In theory, pure water (rain, RO, distilled, etc.) will have a pH of 7, but pure water is a poor buffer, so don't panic if you use an RO purifier and see your pH drop well below 7. Atmospheric CO2 will dissolve in the water some converting to HCO3- and a H+. That increase in H+ is what drives the pH down. So just because you see the pH of your water drop, it does not mean there are pollutants in it. On the flip side, pollutants (heavy metals, bird feces/bacteria, etc.) that rain water may pick up while running off a roof or other surface will have no effect on pH.Pure water will have no PH.

[nc0gnet0]

I live in an area that does NOT have good water for discus. Tap PH is about 8 and hardness is at or above 300.

I'm just now starting to set up for discus and found some 2.5 juvies that I REALLY want. However, I don't have an RO system yet and can't afford the juvies and RO system at the same time.

As an experiment, I tested some rain water that has aged a bit. Hardness was basically zero and PH was a little under 7. I have the capability of capturing and storing large amounts of rain water. Would this be suitable when I find the right mix of rain and tap water to create good discus water until I can get a good RO system?

On a side note: How important are the water parameters for a grow out? I know that I want to breed and the water has to be at certain conditions, but does that apply to a grow out or is massive water changes the only key for the grow out?

Thanks in advance

I have seen a few assumptions on the fact your collecting your water off your roof, is this correct, or do you have a different method?

Rick

[TexMoHoosier]

Pure water will have no PH.

Sure it will. H2O molecules constantly disassociate into OH- and H+ and at equilibrium, the concentration of both is 10^-7 mol/L, hence pH 7. That's the reason water can react with CO2, the CO2 "grabs" an OH- to give HCO3-, leaving a free H+.

[nc0gnet0]

Sure it will. H2O molecules constantly disassociate into OH- and H+ and at equilibrium, the concentration of both is 10^-7 mol/L, hence pH 7. That's the reason water can react with CO2, the CO2 "grabs" an OH- to give HCO3-, leaving a free H+.

Deionized water will quickly acquire a pH when exposed to air. Carbon dioxide, present in the atmosphere, will dissolve in the water, introducing ions and giving an acidic pH of around 5.0. The limited buffering capacity of DI water will not inhibit the formation of carbonic acid H2CO3. Boiling the water will remove the carbon dioxide to restore the absence of a pH value. In practice, the indication from chemical indicators can give a value of usually between pH 5.0 and pH 9.0 depending on the indicator used.

[DJW]

The discussion is revolving around a semantic difference. To say that pure water has no PH is like saying that the room has no temperature because it is neither hot nor cold. A neutral PH of 7 is by definition the PH of pure water, right? Even though its just about impossible to measure such a thing.

The electronic PH probes, especially the cheap ones, have a hard time measuring the PH of very soft water since the glass electrodes need a little bit of conductivity. I will sometimes add a couple grains of salt to settle it down if the probe is in a cup.

[nc0gnet0]

Pure water does not contain any ions and therefore cannot have a pH value (log(0) is infinity). however, if pure water is exposed to air it becomes mildly acidic. This is because water absorbs carbon dioxide from the air, which is then slowly converted into carbonate and hydrogen ions (essentially creating carbonic acid).

https://en.wikipedia.org/wiki/PH

[John_Nicholson]

have you ever recreated his "experiment"
raise 1/2 your batch in the RO waste, and the other 1/2 in regular water and see if you notice difference.

Nope. I never felt the need. I did keep some pairs in 100% ro for an extended period of time. Something like a year. The number abd quality of the fry produce kept decreasing.

-john

[nc0gnet0]

Capturing rain water and then running it through a carbon block filter would be a suitable alternative to using RO water ( you would need to buffer it ), but it becomes problematic on a few different levels, one being that the collection surfaces would need to be kept reasonably clean and not add pollutants. Roofs and gutters in most instances would not be a good collection surface. The other problem is you would become dependent on an adequate amount of rain on a fairly steady basis (or at least have the ability to store large amounts of rain water) to perform regular water changes.

Yes, rain water will pick up some pollutants as it falls through the atmosphere, but ground water has this problem as well, along with also acquiring pollutants as it filters through the soil etc. I think there is a general misunderstanding as to the level of filtration our tap water goes through, it is never "purified" rather it is basically just filtered for sediment,polished and then sanitized with chlorine and or chloramine (there are cases in which additional filtration is required, but this is not the norm)

[TexMoHoosier]

Pure water does not contain any ions and therefore cannot have a pH value (log(0) is infinity). however, if pure water is exposed to air it becomes mildly acidic. This is because water absorbs carbon dioxide from the air, which is then slowly converted into carbonate and hydrogen ions (essentially creating carbonic acid).

https://en.wikipedia.org/wiki/PH
But the definition of "pure" water that is used in that article is a form that does not exist in a liquid state nature. In reality there is no such thing as a water solution without ions. All of the water in a sample of pure water does not keep the form of H2O. Water molecules dissociate into ions (see the water constant paragraph under "calculations of pH" in the same article).

"A complicating factor is that water itself is a weak acid and a weak base (see amphoterism). It dissociates according to the equilibrium...."

Anyway, this was a good debate, but I think we're getting off topic for this thread...

[DJW]

"Pure water" is a singularity in nature, so we would only be quibbling about whether we like the notional definition of PH or the operational definition, where PH can only be measured as electromotive force in the presence of ions other than hydrogen ions.

In fish tanks the problem as I see it is, how do we get a good measurement of PH in water having very low conductivity? Electronic meters work great in salt water but in soft freshwater the PH wanders around undecided. An optical PH meter would be nice to have.

[nc0gnet0]

But the definition of "pure" water that is used in that article is a form that does not exist in a liquid state nature. In reality there is no such thing as a water solution without ions. All of the water in a sample of pure water does not keep the form of H2O. Water molecules dissociate into ions (see the water constant paragraph under "calculations of pH" in the same article).

"A complicating factor is that water itself is a weak acid and a weak base (see amphoterism). It dissociates according to the equilibrium...."

Anyway, this was a good debate, but I think we're getting off topic for this thread...

But the value of the pH of the water in "nature" is in effect a product of it interacting with it's environment, and not of the water itself. Yes, we can argue that unless contained within an inert container and held in a vacuum pure water will indeed have some hydrogen ions (because it is no longer "pure"), we need to understand that when in a pure, or nearly pure state, the pH of the water is very volatile. Simply stating is has a pH of or nearly 7.0 is actually, at least IMO, a disservice, and misunderstood by many.

I can literally add say 50 gallons of distilled or de-ionized water (your definition pH 7.0) to a small volume of water with either an acidic (pH 5.0) or alkaline (pH 8.0) measurement, and the distilled water will have very little impact on the pH value of that small volume of water.

Conversely, you can have naturally occurring water with a pH of 7.0 (ions are at equilibrium) that does have buffering capability. Adding 50 gallons of this water to a small amount of water with either an acidic (pH 5.0) or alkaline (pH 8.0) will have a much greater impact than the above example on the final pH.

So yes, while you can argue that we are debating semantics, this is the reason I bring the subject up.

There is a fundamental difference between a solution (h2o) having no ions or it having its ions in an equilibrius state.

-Rick

[brewmaster15]

we need to understand that when in a pure, or nearly pure state, the pH of the water is very volatile This is the condensed eayy to understand version. There's a reason why water is called the universal solvent.:)

[jkratzwald]

I have seen a few assumptions on the fact your collecting your water off your roof, is this correct, or do you have a different method?

Rick

Emptied the swimming pool (above ground) and covered it with a cover that has holes in the center of it. Center sags, rain water goes into pool and I pump it out as needed. So no pollutants from roof, gutters, etc. This should get me through the winter until I can get an RO system installed and the kids want their pool back!!

So I have large capacity as winters here are very wet. I completely emptied the pool in early october and it already has about 4 inches of water in it. I've been mixing it 50/50 with tap water, and the numbers look pretty good. PH right around 7, hardness between 120-150.

[Skip]

Emptied the swimming pool (above ground) and covered it with a cover that has holes in the center of it. Center sags, rain water goes into pool and I pump it out as needed. So no pollutants from roof, gutters, etc. This should get me through the winter until I can get an RO system installed and the kids want their pool back!!

So I have large capacity as winters here are very wet. I completely emptied the pool in early october and it already has about 4 inches of water in it. I've been mixing it 50/50 with tap water, and the numbers look pretty good. PH right around 7, hardness between 120-150.

Are u water changing with this method yet?

[jkratzwald]

Are u water changing with this method yet?

Yes. Been doing it for for a couple of weeks....... BUT...... I don't have discus in the tank yet. The tank has black angels, cardinal tetras, hatchet fish, kuhli loaches, bristlenose plecos and a couple of corys. Plan on adding some rams in the next week or two to see how they do. From what I've read and experienced, if rams make it, discus will do well. Am I wrong in this?

I don't think I'm going to put the discus in that tank when I get them. I have a 45 that I plan to grow out in, but use the same water. I plan on starting with six 2-3" discus, grow them out as fast as possible with the water changes. If/when I get a pair that wants to pair off, I'll put the others in the big tank that I mentioned above and leave the pair in the 45 to do their thing.