# ro water



## cjacob316 (Dec 4, 2008)

i am strongly considering south american cichlids and i think i'm going to use RO water for the tank

is straight RO water too soft to use directly? i know i can add epsom salt and aquarium salt to bring the hardness up if i need to.

what should the GH and KH be? I'm having a hard time finding something that relates GH and KH to mg/L caco3 and dH, i have seen a chart here relating soft water to measurements in caco3 and dH, and i have seen a chart that has RO water listed at 1 GH and 1 KH, i just don't know how to translate one chart to the other

i hope this makes some sense


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## adam79 (Jun 27, 2007)

The hardness is going to depend on the species, but I think most people use strait RO.


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## aquariam (Feb 11, 2010)

opcorn:

nope. Straight R/O has a kH and gH of zero and no ions of anything. Adding magnesium and sodium isn't going to do much to save you there.

Your fish won't last long in pure R/O.

You have two options, 1 is to mix 50/50 R/O and tap, see what that gives you pH/kH/gH wise, is it stable, do you want it

Use pure R/O and add R/O right and some trace elements.

What's your pH out of the tap? If it's <7.5 most south american stuff will be fine.


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## cjacob316 (Dec 4, 2008)

it's 8.2 and hard

from what i understand magnesium, sodium, and calcium are the main trace elements, and according to this sight, they are all you need to add, and don't need to spend money on premade stuff

in fact those are the ingredients in the ro rite additives


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## aquariam (Feb 11, 2010)

cjacob316 said:


> it's 8.2 and hard
> 
> from what i understand magnesium, sodium, and calcium are the main trace elements, and according to this sight, they are all you need to add, and don't need to spend money on premade stuff
> 
> in fact those are the ingredients in the ro rite additives


I will gladly fork out money for the guaranteed standardization of a premade buffer.

I could make my own instant ocean at home too- but I can't be bothered. I prefer pre-mix.

The option is of course yours. I find R/O right quite cheap especially in powder form in the giganto format.

Of course, you don't need it. If your pH out of tap is high, and especially if your kH is high, mixing it with RO until you get 6.5ish with a kH around 4 or 5, or whatever you're after will work just fine. You can always tweak your kH to lock the pH with a cheap kH solution (or make your own)


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## Chromedome52 (Jul 25, 2009)

Before you can prepare your water, you have to know what species you plan to keep. A lot of people assume that "South American" means black water - it doesn't. The upper reaches of the Orinoco are different from the lower, which is different from the Rio ***** basin, which is different from the Paraguay basin, and that's different from the Peruvian Amazon. Not to mention the small rivers along the SE coast of Brazil, though those mostly contain catfish and Tetras. Temperature, water chemistry, and habitats all vary. We are talking about a whole continent, after all.

Hardness is more important than pH, and for most species that are not blackwater you will want to shoot for about 100-200 ppm of general hardness, or roughly 5 to 12 dGH. "50/50 R/O to tap" is useless if your tap water is liquid rock, but R/O is totally unnecessary if you live in a city that has a good water supply within those parameters. Using oak leaves or almond leaves will keep the pH down, but it's the tannic acids that are added that are of value to control bacteria. I've bred many Tetras and _Rivulus _killifish in this water successfully, as well as several Dwarf Cichlids from the Peruvian Amazon and Orinoco regions.

To simulate blackwater I've used pure R/O, but only after filtering through peat several hours or days. It actually buffers to a low pH, while still avoiding pH crashes. The acidification from peat is humic acid, rather than the tannic acid that comes from some wood and leaves. This works best for extreme blackwater species, such as the Apistos from the Orinoco basin. Blackwater has a hardness near zero just like R/O, which is why plants don't grow in it in the wild. Changes are done from a peat filtered reservoir (mine held about 40 gallons).


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## aquariam (Feb 11, 2010)

To simulate blackwater I've used pure R/O, but only after filtering through peat several hours or days. It actually buffers to a low pH, while still avoiding pH crashes. The acidification from peat is humic acid, rather than the tannic acid that comes from some wood and leaves. This works best for extreme blackwater species, such as the Apistos from the Orinoco basin. Blackwater has a hardness near zero just like R/O, which is why plants don't grow in it in the wild. Changes are done from a peat filtered reservoir (mine held about 40 gallons).[/quote]

That's hard core.
:thumb:


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## Chromedome52 (Jul 25, 2009)

40 years of hard core. :lol:


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## cjacob316 (Dec 4, 2008)

i was thinking bolivian rams and some sort of geo, most of which say <7 pH and soft water

i haven't measured the hardness of my water in a long time, but i know it's pretty hard


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## cjacob316 (Dec 4, 2008)

according to the city, the water has a pH of 8.34 total hardness of 117 ppm


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## aquariam (Feb 11, 2010)

cjacob316 said:


> according to the city, the water has a pH of 8.34 total hardness of 117 ppm


ya bring it down to 7.5 or so.

Bolivian rams look like TRASH below 7. Do best around 7.5

Have no real geo experience.

117ppm @ 8.34??

Where's your water coming from? That's odd


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## Blademan (Sep 20, 2008)

If you have a small tank, maybe it's not too much work, but I found it much more satisfying stocking fish that thrive in the water I have. In your case, CAs or Africans. Just a thought.  I have water close to yours though, and have a few more robust SAs. Nothing as small and delicate as a ram.


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## Chromedome52 (Jul 25, 2009)

The hardness is good, a little peat or oak leaves in the filter will bring the pH down in a controlled manner. It will come down naturally, but that is how you get crashes! I bred Bolivians in harder water, but the pH was around 7.4. Most of the _Geophagus _will do fine in the same range, but they tend to prefer it a bit warmer than Bolivian Rams. The Geos need quite a bit more room than the Rams, too.


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## aquariam (Feb 11, 2010)

I agree with chrome dome. Can you be bothered with getting like a 15 gal black garbage can and a little in-tank filter with peat moss? Run the water through that for like 3 days then add to the tank?

I used to do something similar. That'll work. Cheaper than an RO unit. You may want to add a little kH solution afterwards.

Another, faster option, Seachem acid buffer, again, as above.


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## cjacob316 (Dec 4, 2008)

the alkalinity is over 200 so it buffers the water to a pretty high pH


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## aquariam (Feb 11, 2010)

cjacob316 said:


> the alkalinity is over 200 so it buffers the water to a pretty high pH


Acid buffer. Precipitate that sucka out. :thumb:


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