# High? sulfate levels in tapwater



## spinycheek (Apr 26, 2008)

Weird. I know sulfates in seawater can range close to 1,000 mg/L naturally, but I'm not sure about its effect in freshwater. It certainly could lead to hydrogen sulfide production if the water goes stagnant, be careful about stirring up the substrate because it'll be anaerobic in the bottom layers.


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## plantbrain (Dec 15, 2003)

SO4 is the main anion in tap water, you drink it.
Does no harm nor leads to anaerobic conditions or any of that baloney.
Plants also take up this form of sulfur. 

Anaerobic sulfur reduction bacteria requires, not suggest or not sort of kinda maybe business...........it is obligate anaerobic bacteria, no O2.........

You can add lots of SO4(sulfate), tons of it.......and no reduction, even if the gravel 12 inches deep.

Does not matter, if there's no organic material.

If there's too much organic material, or the loading rate is high enough to cause the bacteria in the soil/gravel use all the available O2, then it can become reducing to H2S.

But you must have a rate high enough to prevent O2 from plant roots, and from the diffusion for that to occur and a large source of reduced carbon.
This is rare in most planted tanks.
Mostly due to dying plant roots/poor plant growth after a period of decent health, not the reducing conditions themselves.
In other words, black stank H2S is a result of poor plant growth in the root organs, which then leads to bacteria consuming all the O2 up(aerobes) eating all that organic carbon(we do the same thing when we eat carbs), which then allows for the sulfur reducing bacteria to use SO4 reduction as an electron acceptor instead of O2 (aerobic). Then you get H2S as an end product.
S-2 is the electron donor.

Heat cable people, power sand proponents, etc rarely have much understanding about the entire process unfortunately.
Good plant root growth cures it, and aquatic plants come from highly reducing sediments in nature, they are well adapted as long as they good growth parameters otherwise, to grow in very reducing anaerobic soils,.

It's not as simple as having just SO4 in tap.
Most harder tap waters are loaded with SO4.

If interested in more:

http://wetlands.ifas.ufl.edu/teachi...ochemical properties [Compatibility Mode].pdf

Dr Reddy is _the_ person to go to for wetland soils.


Regards, 
Tom Barr


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## icegreen (Oct 12, 2007)

Well it is good to know that high levels of SO4 are common in tapwater. I just thought 100 mg/l sounded kinda high compared to levels we run other elements at K:20 mg/l for example. The tapwater around here has always seemed a little strange. Water report shows:
Alkalinity, CACO3: 59.9 mg/l
Alkalinity, Total: 346 mg/l
Hardness, Carbonate 95.1 mg/l
PH: 9.6
Calcium: 13 mg/l
Magnesium: 15.2 mg/l
If KH is around 3 degrees using a test kit why is PH so high? Also with Ca and Mg levels this low, why using a GH test kit do I get around 8 degrees. On the plus side N and P levels are very low so I can add to my hearts content and K is 7mg/l which means I don't have to add as much.


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## KevinC (May 24, 2004)

icegreen said:


> Alkalinity, CACO3: 59.9 mg/l
> Alkalinity, Total: 346 mg/l
> 
> PH: 9.6
> ...


The high Total alkalinity explains your pH. There is something besides bicarbonate that is buffering/raising your pH. I'd say phosphates, but you state that is low. Could be polyphosphates since they won't set off your hobby-grade PO4 test kit. Borate is a possibility as is plain old hydroxide. That is also the pH that the water company sets the water at in the pipes - does it read the same after 24 hours out-gassing at your home?

There are other ions besides Ca and Mg that contribute to hardness - Fe and Mn for example. However, these are usually very low and Fe causes discoloration if too high. Perhaps a bad hardness test kit or a rock in your tank leaching hardness ions?

Re: sulfate - the EPA recommends less than 250mg/L due to odor/taste issues at higher levels. It can also give multi-day guests diarrhea if they aren't used to high sulfates.


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## icegreen (Oct 12, 2007)

The PH of the tapwater doesn't budge no matter how long it sits. No rock just driftwood in tank. Someone a while back had mentioned that the water company may add ash of something or another. Not really having any real problems. Just suffering from a severe case of collectoritis and probably have to come to terms that some plants will flourish and others won't. Mainly just curious about the chemistry of my tapwater in general.


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## plantbrain (Dec 15, 2003)

icegreen said:


> The PH of the tapwater doesn't budge no matter how long it sits. No rock just driftwood in tank. Someone a while back had mentioned that the water company may add ash of something or another. Not really having any real problems. Just suffering from a severe case of collectoritis and probably have to come to terms that some plants will flourish and others won't. Mainly just curious about the chemistry of my tapwater in general.


Well, you can run RO if you want to remove all that, or activated carbon for any organics.

Up to you.

You can also blend the RO with say 50% tap and see.
Not bad if you have a small tank, if you have 500 gallons worth of aquariums, not so practical, ought to just live with it and find suitable plants/fish that do well in the tap.

You can also do a few small tanks with RO and keep a few species you like that do better in soft water.

I've had little issue with hard water, I have soft now, and like it more, but you can do really nice planted tanks etc with liquid rock.

KH of 12, Gh of 24 etc.

Regards, 
Tom Barr


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## icegreen (Oct 12, 2007)

Tom if I may ask, what issues did you have with hard water? Why do you like soft water more now? 
My high tapwater PH of 9.6 used to concern me more than anything. I tried using KH/PH charts to determine CO2 levels, read if you dropped your tapwater PH a certain number of points it meant you had 30 ppm, nothing worked. Now I just add as much CO2 as my plants tell me to. Currently running a PH of somewhere under 6, as low as the test kit goes. Fish and shrimp are happy and not stessed. Okay change that. The Sawbwa Resplendens clearly suffered and I had to get rid of them. 
No problems with dropping PH to what I assume is a really low level from a really high level in your view? Or running a really low PH in general? I really appreciate your help.


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