# Super soft water and CO2



## Emily6 (Feb 14, 2006)

Hey folks- I have CO2 injection on my tank and with a starting pH of 8 and a GH of 0, KH of 3. Even when the CO2 brings it to 6.5 the indicator is still bluish. I've never seen my plants pearl. :-(

I'm nervous to add more CO2 and make the water too acidic. I have a pH indicator (Milwaukee) that I re-calibrate every few months. Occasionally I dose with Equilibrium but at 1 tb for every 3 dh per 20 gallons per week, I'd be dosing a lot on a 65 gallon tank.

Is there a better answer? I know people use dolomite or crushed shell but I worry that these would become exhausted before I felt like redoing the substrate. How long does it last for? Can I put something like that in the filter instead? Would it do enough?


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## aquabillpers (Apr 13, 2006)

It would seem that the main problem is that the plants are starving because of a lack of minerals.

Assuming that your GH test kit is correct (you should check it), you should add enough Equilibrium to raise the GH up to at least 3, measured immediately after you add it. 

If the GH continues to drop rapidly, there must be something in the tank that is consuming it, like many snails or shrimp. 

Your KH is OK, but if you want to increase it, use baking soda. That gives you better control than crushed minerals.

Please let us know what happens.

Good luck.

Bill


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## Emily6 (Feb 14, 2006)

Thanks for the advice- I actually bought a new test kit because the results were suspiciously low. But I have no real reason to think they're wrong- we NEVER get mineral build ups on anything. 

I have no shrimp or snails so I think I'll continue adding the equilibrium until i run out- then go to baking soda or something.

I'm still interested in something slow-releasing I can put in the filter, though.


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## aquabillpers (Apr 13, 2006)

Emily6 said:


> Thanks for the advice- I actually bought a new test kit because the results were suspiciously low. But I have no real reason to think they're wrong- we NEVER get mineral build ups on anything.
> 
> I have no shrimp or snails so I think I'll continue adding the equilibrium until i run out- then go to baking soda or something.
> 
> I'm still interested in something slow-releasing I can put in the filter, though.


It's not about using Equilibrium or baking soda. The former affects GH only and the latter, KH only.

You need to get your GH under control before you worry about anything else.

Maybe rethink putting slow (unknown?) release stuff in your filter. It's easier just to add minerals as you need them, which isn't very often.

Here's a link to an overview of aquarium water chemistry. http://www.americanaquariumproducts.com/aquariumkh.html

(If it contradicts anything I've said, it's wrong. <g>)

Bill


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## neilshieh (Jun 24, 2010)

just a heads up, for api test kits you NEED TO SHAKE really well, if you don't shake.... you won't get the correct measurements and it can be off by quite a lot.


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## Emily6 (Feb 14, 2006)

I don't think mine's API but I did give it a good mixing. I have no reason to think I don't have super soft water, though- I've NEVER cleaned my shower head in over 3 years. And it's still twinkling clean.

Right now I'm trying to pick a new substrate- I see a lot of them reduce the GH and I clearly don't need that. Suggestions welcome. The only color I don't like are the reds/clay colored substrates.


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## aquabillpers (Apr 13, 2006)

Dear Emily,

i have hard water and I have never needed to clean my shower head, and it still works fine. Perhaps you need a different metric?

I used API test kits for years, when I was into testing. The GH kit has a shelf life of no more than two years, and probably less.

I never heard of a substrate that reduced GH; if they do anything, they increase it as they dissolve, if they do.

It's better to choose a substrate based on its intended function rather than its color.

Did you visit that web site I sent you in my last posting? If you don't develop a better understanding of basic water chemistry, you are in for a lot of frustration in this hobby.

Good luck!

Bill


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## Emily6 (Feb 14, 2006)

The test kit is 1 year old- I bought it last year when I thought I'd tackle this initially. I did look at your link- I'm actually a water ecologist professionally -which isn't to say I'm a chemist- and I've been doing this for 13 years (which is still nothing compared to some people). I'm really looking for experience to lean on. Thank you for the information nonetheless- I could always use a refresher.

I disagree about color since what's the point of setting up a beautiful aquascape if you think it's jarring to the eye? Color is unimportant I suppose if you plant to grow a lawn over it or basically farm your plants but that's not my plan. Regardless, I didn't realize until recently how popular so many non-substrate materials have become as substrate, making the selection process a little daunting.

Even commercially available aquarium substrates are advertised as lowering water hardness:

"It decreases water hardness and lowers the pH level to a degree at which most aquatic plants grow comfortably."
http://greenleafaquariums.com/planted-aquarium-substrate/up-aqua-soil-substrate.html

here's another with basically the exact same statement (looks like the same product repackaged for ADA):

http://http://www.adgshop.com/Aqua_Soil_Amazonia_p/104-031.htm

Anyway, what I meant by my statement about Equilibrium is that I plan to get my GH under control- it's the only one of the 2 that's not so great- and then see where I'm at (which might involve baking soda to adjust kH- maybe not). I realize that wasn't exactly clear.

If I need to continue to dump Equilibrium in the tank, I might find something like dolomite better. But that's what I'm asking- can I put dolomite in the filter? How long before it's spent? Is there a better long term solution (years worth) than Equilibrium or dolomite?

Phewf... think I tired myself out on that one. Sorry! Seems I'm strayed from the initial topic a bit.


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## Diana K (Dec 20, 2007)

Emily, there are 2 things called hardness. 

GH, General Hardness, is a measure of Calcium and Magnesium in the water. 
These are minerals the plants and fish need. When the GH is so low (under 3 German degrees of hardness) you should also be suspicious that you might be totally lacking either Ca or Mg. 
Seachem Equilibrium, Barr's GH Booster and Kent RO Right and other products contain Ca, Mg and sometimes other minerals (often potassium). 
These materials do not affect the pH. 

KH is Carbonate Hardness. Carbonates and bicarbonates are the most common buffer of pH in aquariums. Some plants can use carbonates as a source of carbon, and nitrifying bacteria need carbonates. They get their carbon from carbonates. 
As a general guide high carbonates will stabilize the pH on the alkaline side of neutral, low carbonates allow the pH to vary, so that anything else in the water can alter the pH. For example, adding CO2 will lower the pH. 
The most common source of carbonates added to an aquarium is baking soda, Sodium Bicarbonate. This material will not alter the GH, it has none of the minerals (Ca, Mg or anything else) the plants need. Just carbonate. Some people worry about the sodium. Another source of carbonates is potassium bicarbonate. This would add a small amount of potassium (a necessary plant nutrient) as well as the carbonates. 
Carbonates and bicarbonates are slightly different, but they are sort of interchangeable as far as aquariums go, one can change into the other in the tanks. 

You can add these materials:
Coral sand, Oyster shell grit (sold for caged birds), limestone or any related material like dolomite. 
You can put these in a bag (I use a nylon stocking) in the filter. 
The change is slow. 

The way I do this for hard water tanks:
Prepare the water ahead of time. 
Add Equilibrium for GH.
Add baking soda for KH. 
Add dechlor. 
Circulate the water overnight if possible, though these materials will dissolve fairly fast, and as little as a few minutes prep is OK. 
Make the new water to be the parameters I want in the tank. 
Do the water change. 

The materials in the filter are more of a stabilizing influence. If the plants or fish start using the Ca, Mg or carbonates, and the pH starts to drop these materials will dissolve, adding these things to the water. Do not depend on these to adjust the water for you when you do a water change. You would be subjecting the fish to too quickly changing mineral levels on the day of the water change. 

There are substrates that will remove carbonates. Soil Master Select, Turface, Safe-T-Sorb and some of the ADA products can do this. Lowering the KH allows the pH to drop. 
In some of my tanks the substrate removed all the KH (tests showed zero) and this allowed the pH to drop below the test results. Recently I got a different test, that shows results even lower and the pH in one of these tanks was about 5.5.

Yes, there is a longer term solution: Buy a house in an area with slightly harder water.


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## aquabillpers (Apr 13, 2006)

Good summary, Diana K!

My problem with adding dolomite and similar substances in an attempt to increase GH is not only are they slow acting but also their use makes it harder to control the degree of hardness, particularly if they are made part of the substrate. Adding a powder every now and then is safer, IMO.

ADA and other vendors market substrates that do reduce KH, but no one offers a substrate that controls GH. I posted that question to Tom Barr's forum, and here's the result:

http://www.barrreport.com/showthread.php/10749-Does-Aquasoil-reduce-hardness?p=87797#post87797

I like the idea of checking the hardness of the water before moving to a new home. 

Bill


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## Zapins (Jul 28, 2004)

A good summary Diana K

Bill, why not use magnesium sulfate and calcium chloride? These two are very common, cheap and dissolve nearly instantly and will only affect the GH without adding anything else. We even have a calculator (the fertilator) on the top left of APC that will help you calculate dosages and the resulting concentration in your tank.

I wouldn't use baking soda to buffer. Sodium is really quite nasty stuff for plants, it will block the uptake of Ca/Mg/K very effectively. So you will see Ca/Mg/K deficiency symptoms in your plants when you actually have a sodium toxicity. Much better to use potassium carbonate or calcium carbonate to buffer, or simply don't worry about the KH at all, it isn't that important and many people go through great pains and expense (RO/DI systems) to get 0-2 KH.

Also, using dolomite or shells/coral will last quite a while. You can use a small bag for several weeks.

After reading your original post I'm actually unsure why you want to change the parameters so precisely. You never said your plants were not growing well, only that they don't pearl. Pearling has nothing to do with the vitality of the plants and everything to do with oxygen saturation in the water. If you have decent surface agitation it will prevent the water from becoming supersaturated with oxygen which prevents the plants from pearling. If you change your water and there is a lot of O2 in the new water (supersaturated from being underground at 55F where more O2 can dissolve into it) the plants will suddenly pearl.


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## aquabillpers (Apr 13, 2006)

Zapins said:


> A good summary Diana K
> 
> Bill, why not use magnesium sulfate and calcium chloride? These two are very common, cheap and dissolve nearly instantly and will only affect the GH without adding anything else. We even have a calculator (the fertilator) on the top left of APC that will help you calculate dosages and the resulting concentration in your tank.
> 
> I wouldn't use baking soda to buffer. Sodium is really quite nasty stuff for plants, it will block the uptake of Ca/Mg/K very effectively. So you will see Ca/Mg/K deficiency symptoms in your plants when you actually have a sodium toxicity. Much better to use potassium carbonate or calcium carbonate to buffer, or simply don't worry about the KH at all, it isn't that important and many people go through great pains and expense (RO/DI systems) to get 0-2 KH.


Zapins,

I am blessed with moderately hard water, so I don't have to add anything to maintain acceptable GH and KH. For a while I was experimenting with soft, acid water from a nearby swamp, and I used Equilibrium to add the required minerals. I still have most of that jar.

If for some reason one had to increase GH regularly it would make sense financially to "mix your own" hardness booster.

Using baking soda has long been the standard way to increase KH. While it does add sodium to the water, it doesn't add very much. It's a question of degree.

I agree about KH, although at high levels - 8.5 or higher - it starts to interfere with plant metabolism. At very low levels the lack of buffering can lead to rapid pH swings, which can be harmful to fish.

Bill


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## Emily6 (Feb 14, 2006)

Wow, that's a lot of info! Thanks!

Zapins- my plants are growing _ok_ but my CO2 indicator is usually bluish and my feeling was that the plants not pearling ever supported my thoughts on a potential CO2 shortage- I have my CO2 hooked up to a pH monitor so the pH is dropping so quickly that the CO2 isn't on long enough (I suspect). Yes, I have kept it in calibration. I do realize that pearling isn't the end all be all of plant health but it was an observation I was using it in conjunction with other clues.

So it would seem I should just stick with my water change routine including Equilibrium and think about adding a bit of baking soda. I see Big Al's sells a large bucket of Equilibrium...

In my quest for a new substrate, I might want to avoid all those listed as removing the carbonates. Unless I wanted to make my issue worse.

Currently I'm using Flourite sand. I've heard good things about cheaper products one can charge then add- any that might fit my needs? Seems like most of them are on the carbonate removing list.

Thanks guys!


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## Diana K (Dec 20, 2007)

Cheaper substrates that do remove KH are usually the Oli-Dri and related products. Soil Master Select and Turface are spin-offs of the oil absorbent product line. Kitty litter is another related product. Mostly I hear about how it falls apart in the tank, rather than any carbonate removal. 

Expensive materials that do this include the ADA product line. 

Cheaper substrates that are neutral are most of the sands and gravels you can pick up at local rock yards, masonry stores and so on. Bring baggies and a sharpie pen and get samples and test them at home. Some may add minerals and raise the pH. 
Good things to look for:
Pool filter sand, blasting sand, sand you might pick up at a nearby lake or the ocean. 

There are a lot of posts about using potting soil as aquarium substrate. If the potting soil is high in peat moss it might remove some minerals from the water. Often the instructions about these substrates include 'Add Dolomite' or something. This is to counteract that tendency to remove minerals. If the dosing of dolomite is right these materials will be neutral. Not remove, not add minerals, or alter the pH. 
____________________________________________

Over time the natural reactions in an aquarium tend to remove the carbonates and lower the pH. The little bit of baking soda that you might add to correct this adds only a trace of sodium, but, if you do not want to add even that trace then use a carbonate source that is linked to something you want to add anyway, such as potassium bicarbonate. 

Add to the filter to add small amounts of minerals:
Coral sand (aquarium stores)
Limestone sand or fine gravel (rock yards). Rocks and sands may have any of several names, some names have no clue that it might be a limestone type of rock. Take some acid with you, for example API nitrate test #1 bottle. Put a drop on the rock. If it fizzes, take a sample home for further testing. 
Oyster shell grit (Pet stores, sold for small caged birds)
Aragonite substrate (Awuarium stores, sold for marine tanks)
Cichlid Substrate (Aquarium stores, sold for Rift Lake tanks)


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## Emily6 (Feb 14, 2006)

Ok, thanks for all that info-

When you say blasting sand, does this include coal slag? I like the color of coal slag and it was something I was considering.

I use to have an el natural tank but was really fed up with the layers becoming mixed every time I moved a plant. For the same reasons, I'm looking for a really simple, single layer substrate solution. I'm not entirely unhappy with my flourite sand but it is pricey and does compact rather easily.

Something as close to inert as possible sounds ideal- I'm ok with adding baking soda and in fact used to do that as part of my routine. 

I'll look into those options.


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