RO vs Tap Water

[salman]

I keep reading on different forums and topics about RO water, i never figured out what it was until i was in this discus fish website and it showed pictures of it. We have that in our house. I use tap water for my aquariums. Do you think i should keep with the tap water? or use the 'RO'? Most of my fish require soft water, Is RO soft?

Any help would be highly appreciated :)

[salman]

I also have trouble testing for hardness. I bought a water test kit, it tested NO2 GH KH pH and CO2. I figured out how to test everything but the hardness. There were 2 different kinds of hardness, General Hardness (GH) and Carbonate Hardness (KH) Which one do i test for the hardness everyone talks about?

[zackish]

I also have trouble testing for hardness. I bought a water test kit, it tested NO2 GH KH pH and CO2. I figured out how to test everything but the hardness. There were 2 different kinds of hardness, General Hardness (GH) and Carbonate Hardness (KH) Which one do i test for the hardness everyone talks about?

General Hardness.

[salman]

How can i lower it? The General Hardness says its 20 right now.. And my discus fish need to be in between 1-6 :S ... Is the RO water soft??

[zackish]

How can i lower it? The General Hardness says its 20 right now.. And my discus fish need to be in between 1-6 :S ... Is the RO water soft??

RO stands for reverse osmosis I am not sure but I think that is for the KH which has to do with the PH buffering levels.
However, 20 is not high at all. Many people need to realize that fish can tolerate a wide range of water parameters.

[kkyyllee]

discuss can tolrate hard water, yours is fine

[salman]

But they look stressed and not all of them look very healthy. In most of the discus websites say the water has to be really soft. My RO filter's hardness is at 6. How much of the RO water can i put it my aquarium so it wont do any damage to the fish?

[zackish]

But they look stressed and not all of them look very healthy. In most of the discus websites say the water has to be really soft. My RO filter's hardness is at 6. How much of the RO water can i put it my aquarium so it wont do any damage to the fish?

Where your fish healthy when you bought them?
Is your tank fully cycled? (0 ammonia, 0 nitrites, some nitrates?
If your other levels are off this could be causing some stress and you might want to test some of that.

[Rue]

I keep reading on different forums and topics about RO water, i never figured out what it was until i was in this discus fish website and it showed pictures of it. We have that in our house. I use tap water for my aquariums. Do you think i should keep with the tap water? or use the 'RO'? Most of my fish require soft water, Is RO soft?

Any help would be highly appreciated :)

R/O water is very pure. It has nothing in it. As such it ISN'T the best choice for FW tanks...you want the minerals that are in the tap water...just use a water conditioner to bind/dissapate the toxic materials.

For SW you use R/O because you need to start with pure water...you ADD all the minerals you need with the synthetic salt base that you add to it...

[zackish]

ANd if you look up on-line and read like I just did you would learn that R/O divides the water and the particles like RUE stated. It is like a seperating membrane. The example the article used was gore-tex boots. They let water vapor in but not the liquid molecules...therefore your feet not getting wet.

[salman]

I changed 50% of my aquarium water to RO water. Then i came here to see if anyone wrote anything and everyone is telling me that its not good. But when i baught my fish they were all good looking and bright, I was looking at my fish earlier today and some of them turned really dark. Now after i put the RO water, some of the black turned into turquoise and its been like 30 minutes since i change the water. Should i not use RO water again for my next water change? Because my discus fish need really soft water and my tap water is really hard. I am soo confused i dont know what to do. I think that the hard water is causing them stress and ive seen alot of stress symptoms like color fading, and some black/grey colors on my lighter discus fish.

Please tell me what to do :S:S

[salman]

Cant i use like 50% RO and 50% tap? so i can have both soft water and all the things i need from the tap water?

[Rue]

RO water is soft...

...I'm just not sure how you then make sure your fish get the minerals and whatnot that they need...

I think you should go on a discus forum and ask...discus are very finicky and I just don't know enough about them to really give you any specific advice...

[salman]

Where your fish healthy when you bought them? Pretty Sure


Is your tank fully cycled? (0 ammonia, 0 nitrites, some nitrates?
My test kit only has a test for nitrites, and it says it has <0.3



If your other levels are off this could be causing some stress and you might want to test some of that.

My pH is between 5-7. Depending on how much water i change daily.

[zackish]

Where your fish healthy when you bought them? Pretty Sure


Is your tank fully cycled? (0 ammonia, 0 nitrites, some nitrates?
My test kit only has a test for nitrites, and it says it has <0.3



If your other levels are off this could be causing some stress and you might want to test some of that.

My pH is between 5-7. Depending on how much water i change daily.

That is your problem...your PH is fluctuating WAYYYYYY too much like insanely.

[salman]

The pH isnt changing alot.. Its usually at 5. But when i do a 10-20% water change it gets to 6 because my tap water is 7. But i did a 45% water change today and the pH got to 7. But it will go down to 5 really fast because i have wood inside my aquarium.

[salman]

How can i get my pH to stay stable?

[zackish]

How can i get my pH to stay stable?

When you do your water changes you need to keep your PH the same with the water your adding somehow. Maybe put some PH down buffer into the water that you will be adding.
YOu also gave me a good point that I need to check out on my tank. After being setup for about a week with fish in it i have no clue what the PH is now compared to my tap.

[dev]

You should never use RO or DI water on its own. Mix with tap water, or at least add some calcium and magnesium sulfates.

That kind of fluxuations in pH is just no good. Remember, water with a pH of 6 is ten times more acidic than with a pH of 7. A sudden change in pH by 1.0 or more could seriously stress your fish. To keep the pH more stable, do smaller water changes, reduce the amount of pH reducing materials in your tank, lower the pH of the new water (using parts of RO or DI water or ph reducing acids like oak bark extract) or add at least some buffer capacity to the water already in the tank. A fairly stable pH of 6.5 - 7.0 is a lot better than one that bounces between 5 and 7. Discus appears especially unhappy with sudden changes in the pH. As gm72 often puts it; stability is the key.

Adjustments to the hardness must also be done gradually, maybe one or two degrees per day. Some would say less. A GH of 20 german degrees hardness is a little high, but sudden changes in any of the primary water values (pH, GH or KH) will do a lot more damage than a little hard water.

[zackish]

What does Reverse Osmosis actually do to the water? I thought it just take the salt or hardness out? How would that adjust your PH?

[dev]

What does Reverse Osmosis actually do to the water? I thought it just take the salt or hardness out? How would that adjust your PH?

Reverse osmosis also removes carbonates and other pH buffers. Destillation will remove just about anything. Depending on the original water chemistry doing either may lower the pH.

While the theoretical pH of pure water is 7, you will find that distilled water tests at around pH 5.8. This is due to small amounts of dissolved CO2.

Water from reverse osmosis will have no dissolved gasses, but as soon as it is exposed to air, soluable gasses present in the athmosphere, like oxygen and co2 wall start to diffuse into the water, this process is greatly acellerated by movement in the water surface.

On a sidenote, when mixing in a significant amount RO water (such as 50/50), it's a very good idea to oxygenate it before putting it into the tank.

[salman]

When you do your water changes you need to keep your PH the same with the water your adding somehow. Maybe put some PH down buffer into the water that you will be adding.
YOu also gave me a good point that I need to check out on my tank. After being setup for about a week with fish in it i have no clue what the PH is now compared to my tap.

PH down buffer? There is something that can lower the pH?

My water is at 7 pH. But when i put it in the water, the next day when i check its at 5. I dont know whats lowering it. I have wood inside my fishtank, alot of it. It that messing with the pH?

[salman]

I just checked the pH right now and it reads 6. Yesterday when i checked it was at 6.5. Its going down slowly and im sure when i check tomorrow its going to be at 5. I am going to do small water changes like only 10% when the pH gets to 5, so the pH wont get any higher then 6. Will that be okay for my fish tank?

And does anyone know if i should have tap water only which is 20 hardness which is way too high for my discus fish, or use use RO water which is perfect hardness for my discus, but they dont get minerals. Can i put 50% 50% which is what i have right now? Do the fish get enough minerals?


Currently the
pH is at: 6
Hardness is at 13.

the pH lowered .5 from yesterday and the hardness is stable.

[NeonJulie]

Sounds like the alkalinity buffering is a problem - you could easily try some crushed coral in a mesh bag in your filter. The kH is what keeps pH from fluctuating rapidly. It may slightly raise your pH depending on how much you use, but it's reported to stabilize pH, and it's natural and consistent.

I DO use mostly RO water, and I buffer it beforehand with baking soda, for the buffering capacity/kH and to match the pH to my tank, but also use some of my tap water as well.

I personally choose to use the pure water, not necessarily because I don't like my tap values, I'm happy with them, they are similar to my buffed bottled water - but I don't trust my water, I have good reason to think there is something in it, because since I switched to more bottled and wean the bad water mostly out, it appears the fish have really improved.