# Buffering pH with substrate.



## hideandseek (Jul 22, 2009)

Alright, so I've come to find that the water where I will be staying this fall at college is very hard. I'll be setting up a tank with Tang cichlids and so far I have bought just about everything I will need besides fish. One thing I still need is a way to buffer the water to the right pH. I have read that aragonite and crushed coral will do this, however when I went to my LFS (petsmart/petco) the aragonite they had was very course, sharp, and generally didn't look like something I would want to add to my fish tank with $10+ per fish price fish in it. I've also done some searching and have read recommendations of not using crushed coral because it was large and would work its way to the top over time when mixed with sand.

I've bought some quikrete medium sand and would like to use it because it is a bit more coarse than pool sand or play sand, but how can I buffer my water while still using this sand? Do they make fine(r) crushed coral/aragonite?

I've found this but this is for marine setups right? I can't use this for freshwater.

The library also lists eco-complete. How much of this would I need in my 38 gallon to correctly buffer the pH. Would it be possible to mix it with the sand I currently have and use less to save money?


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## Oscar Madison (Mar 24, 2008)

The substrate I found at LFS was marked on the bag for use with African Cichlids. It is basically a bunch of crushed coral and small shells. Excellent buffer


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## reflexhunter (Jul 25, 2009)

i'm no expert but you could try to use limestone rocks to help buffer your ph.


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## S&amp;T (Jul 27, 2009)

Tuffa rocks work pretty good as well.


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## Rockydog (Oct 21, 2007)

Since you say your water is very hard to start with you may be ok as is. Just get a good liquid test kit (make sure it's not out of date) and do a series of tests on the water before you continue to increase Ph, Kh, and Gh.

Limestone (not sandstone), aragonite, and crushed coral is used to buffer Ph but it is a very slow process as it has to dissolve in the water and if you do a large water change it can take a very long time to bring the Kh back up to the required level.

First off determine what your fish require. If they require a higher Ph and hardness you will need

1) bicarbonate of soda to raise Ph (will only raise to a max of 8.2) and Kh which is your buffer to keep Ph from fluctuating called Carbonate hardness best if kept between 5 dH and 10 dH

2) Epson Salts to increase your hardness of the water which is called General Hardness - again depends on fish requirements

3) Sea salt - for overall fish health and recovery from injuries and to replace trace elements.

Take a 10 gal container (I used my hospital tank) with fresh tap water and add 1 tsp soda, 1 tsp epson salts and 1 tsp sea salt, aerate for 30 minutes and check your Carbonate hardness and General hardness.

Add more soda and epson salts to get your Carbonate and General hardness at the level you want. No need to increase the sea salt, 1 tsp / 10 gal seems to work for me.

Once you determine the formula you need prepare the solution for the size tank you have in a separate container and slowly add to the tank (over the course of 24 hours).

When water change time comes predetermine how much you are changing ie 30 gal and have prepared the formula necessary and add gradually as your refilling the tank.

Do not add salts when replenishing evaporated water.

Bicarbonate of soda is baking soda, find in the baking section of any grocery store. Epson salts usually in the pharmacy section. Sea salt also in pharmacy section ie Walmart, have only been able to find large crystals so I just break down dry in a blender so it is easier to measure and dissolve when preparing your formula.

Hope this helps.


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## Cichlidaevid (Jul 27, 2009)

The post above is chock full of good information.

I'd like to add that you could simply put some crushed coral into your filter and it will slowly buffer the water as well. That being said, it should also be noted that as long as your water is hard already, you probably won't need much buffering (if any).

People make a huge deal out of getting the GH and KH up high in an African cichlid tank in an effort to have the same water as what they have in the wild. Ask yourself if the fish you are getting are going to be truly wild-caught. Even if they are, they can be acclimated to reasonable GH and KH levels quite easily. I've kept African cichlids for years without ever adding any kind of minerals, salts or buffering powders at all. Granted, my water here is coming out of the tap at 7.8 PH and has a slight hardness to it.....but it's nothing as high as the KH and GH many people strive for. (My African cichlids look great, and breed constantly, too.....)

I myself think that's one of the great things about keeping African cichlids: The water requirements are pretty easy to achieve. In my case, tap water and a bit of Prime for dechlorination/chloramine removal is all I've ever done, with fantastic results!

Less can indeed be more....


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## Oscar Madison (Mar 24, 2008)

Yep limestone works well too.


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## hideandseek (Jul 22, 2009)

I am in no way worried about the hardness, only the pH. I'm sure I will have to see what the pH actually is before I take major steps to adjust it, but if it does need to be adjusted I would like a good buffer when doing water changes so it doesn't fluctuate.

Cichlidaevid, you mentioned something about adding crushed coral to the filter. Would I be able to get enough into my fluval 304 to do any good? Would it need to be changed at all?


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## Cichlidaevid (Jul 27, 2009)

Sure it will do some good....it certainly can't do any harm. In fact, if you place it where your biological media is, it will grow beneficial bacteria on it and help in that regard as well. You shouldn't have to replace it until it dissolves, which will take a very, very looooong time. (We're talking years here.....)


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## Number6 (Mar 13, 2003)

hideandseek said:


> I am in no way worried about the hardness, only the pH.


It is supposed to be the exact other way around... pH can be largely ignored but GH and KH must be within acceptable ranges (which is a wide range by the by). Sure, a pH ridiculously out of the normal range might not be wise, but it's also incredibly rare if not out right improbable if your KH and GH are within the range.

Focusing on pH and not KH can lead to things like pH bouncing around or avoiding perfectly harmless actions like injecting CO2 into planted tanks, etc.

Hope that helps.


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## hideandseek (Jul 22, 2009)

Wait, when you talk about buffers are you talking about buffering the GH and KH or buffering the pH? I just went through the most rigorous chemistry class of my life in which pH of solutions was a big unit, so when you talk about buffering I'm thinking that you're talking about keeping the pH constant.

If you are talking about pH buffering I have a long response waiting for you, otherwise you might be safe.

I'm not sure if or how buffers for hardness work, because dissolving calcium/magnesium in the water by adding aragonite or crushed coral would raise the hardness. But doesn't it dissolve when the pH is below a certain point? This whole thing is really confusing.

Is the aragonite/crushed coral meant to raise and buffer pH or raise and buffer hardness?


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## Number6 (Mar 13, 2003)

*hideandseek*
generally speaking, KH and pH are linked... KH is calcium carbonate, and is basic so it resists anything making the tank water acidic. This keeps the pH stable more or less, rare exceptions aside.

GH measures calcium and magnesium. Often grouped along with the KH and words like buffering, even though it's a rather confusing jumble of terms by the time we are done! LOL


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## 24Tropheus (Jun 21, 2006)

If your tap water has a high KH it will have a stable and highish pH so you have no need of buffering substrates or to add buffers etc given normal water changes.

I do hate to see folk waist money. :wink:


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## hideandseek (Jul 22, 2009)

Alright #6 thank you very much. What you're saying is exactly what I was thinking I just didn't understand at first because you were saying it a little differently. That being said, I will wait until I can test the water before trying to change the pH, KH and GH at all to see what I have for a baseline before I go jumping into things.

Or would it just be worth it to get something to buffer and not worry about it? As long as its buffering it and not raising above to high I should be fine.


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## 24Tropheus (Jun 21, 2006)

I like to understand what is happening in my tanks and tap water (this may not always stay the same from season to season) so I test. GH and KH and conductivity (and like to measure and adjust if needed water change water to the levels I want before adding it), nitrate etc I do know folk who just use buffering substrates or just crushed coral in the filters and never ever measure anything other than temperature and just do large regular water changes and have great success.

As to which is best? Dunno I like my way I think it gives a more stable environment. :wink:


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