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Discussion Starter · #1 · (Edited)
I've been testing a new cycling tank and found the PH to be high, likely in the 9+ range. We moved into a new house last year and it has it's own well. There was a strong egg (sulfur) odor so we installed a hydrogen peroxide (H2O2) system in lieu of chlorine. The smell and taste are gone. The problem is that H2O2 causes the water to become very alkaline.

I don't think I have the space to install an RO/DI system which would help to lower but not completely balance the PH. My other option would be to buy the water for every change. Natural PH lowering solutions will not be strong enough and will take time. A water change with high PH will shock the system if I am able to get it neutral.

Does anyone have any suggestions or is buying my neutral RO/DI water my best bet?

Thanks
 

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Why does adding peroxide cause the water to become alkaline? My impression is that peroxide is acidic, so it should lower the pH at least slightly when added to water.
 

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Discussion Starter · #3 ·
Why does adding peroxide cause the water to become alkaline? My impression is that peroxide is acidic, so it should lower the pH at least slightly when added to water.
That was what I read, but after seeing your post I did another search and found this on Wikipedia fwiw.

Pure hydrogen peroxide has a pH of 6.2; thus it is considered to be a weak acid.

If that's the case then I wonder what could be causing my well water's PH to be so high. I also use a water softener which should only change it slightly, but may affect the hardness. I'll have to test some water from the outside hose that has bypassed my system.
 

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Most well water is hard, because it usually comes from limestone or dolomite aquifers, and the water is normally slightly acidic, from the CO2 in the air, before it ends up in the limestone, so it dissolves a lot of calcium and magnesium from that source.

Water softeners make water that is not good for a planted tank. You should use the water that doesn't go through the softener. Hard water is good for many plants and fish, much better than softened water.
 

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Most well water is hard, because it usually comes from limestone or dolomite aquifers, and the water is normally slightly acidic, from the CO2 in the air, before it ends up in the limestone, so it dissolves a lot of calcium and magnesium from that source.

Water softeners make water that is not good for a planted tank. You should use the water that doesn't go through the softener. Hard water is good for many plants and fish, much better than softened water.
Water softeners add chlorides which are toxic at very high levels to plants/fish.

On another note peroxide itself does not contribute to pH,it is a strong oxidizer.It may convert some inorganic salts to oxides which can act as acids/bases. Depending on the relative ratios you end up with an imbalance. Vinegar is a cheap and safe way to make the pH acidic - that' s what I would reccommend to get below 7.8.

You should address water hardness separately - I think GH is less important, KH is more crucial and this could actually be in a decent range for your water. Mixing RO water would be a good option to reduce KH/GH. If you don't plan on doing a LOT of water testing buy some Tetra test strips - they will give you pH, KH and GH all in one.
 

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Post the GH, KH, pH and TDS of all the ways you can get water at your home:
Well water, no treatment.
Well water after one treatment (which one happens first?)
Well water after both treatments.

Then, run some of each water into a container and let it sit. Test each container at 24 hours and 48 hours. Lets see what a simple treatment like letting it sit, exposed to the air will do.
 

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Discussion Starter · #7 ·
Post the GH, KH, pH and TDS of all the ways you can get water at your home:
Well water, no treatment.
Well water after one treatment (which one happens first?)
Well water after both treatments.

Then, run some of each water into a container and let it sit. Test each container at 24 hours and 48 hours. Lets see what a simple treatment like letting it sit, exposed to the air will do.

Will do. I won't be able to get water after one treatment as the H2O2 is connected directly to the softener. I can get pre-treated from the outside hose but there is no internal pre-treatment spigot. That will make for some difficulty during the winter as I can't run water outside.

Thanks for the help everyone
 

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It's my understanding that chlorine and H2O2 systems just oxidize the metals in the water and precipitate them out so a filter can remove them. They do nothing with the carbonates remaining in the water. That would explain the high pH. Well water is typically very high in carbonates.
 

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Discussion Starter · #9 ·
Post the GH, KH, pH and TDS of all the ways you can get water at your home:
Well water, no treatment.
Well water after one treatment (which one happens first?)
Well water after both treatments.

Then, run some of each water into a container and let it sit. Test each container at 24 hours and 48 hours. Lets see what a simple treatment like letting it sit, exposed to the air will do.

Well water no treatment:

KH - 17 drops (off the chart)
GH - 23 drops (off the chart)
TDS - 333
PH - 7.6
Ammonia - .5
Nitrite - 0
Nitrate - 0

Well water after both H2O2 and softener treatment:

KH - 18 drops (off the chart)
GH - 1 drop (17.9 ppm)
TDS - 415
PH - 8.4
Ammonia - 0
Nitrite - 0
Nitrate - 0

Can not do test after only one treatment.

Based on those results what is your experienced opinion?

Thanks
 

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You need to test the well (no treatment) after it has sat out for 24hrs. My guess is it comes up a little after it sits out. Let it sit out in a cup or something and then test it the next day.
 

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Softeners replace Ca and Mg ions with Na or K ions, but the carbonate ions remain. So, your KH is about the same after softening as before, and your GH is near zero as it should be, since sodium isn't a hardness ion. I don't see a problem, other than that softened water isn't good for an aquarium.
 

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KH - 17 drops (off the chart)
GH - 23 drops (off the chart)
TDS - 333
PH - 7.6
Ammonia - .5
Nitrite - 0
Nitrate - 0

Well water after both H2O2 and softener treatment:

KH - 18 drops (off the chart)
GH - 1 drop (17.9 ppm)
TDS - 415
PH - 8.4
Ammonia - 0
Nitrite - 0
Nitrate - 0
I would use the well water before treatment and keep fish that like hard water. Use Prime or other dechlor that locks up ammonia, or get a product that just locks up ammonia.
Keep the outside source protected from the cold and fill a garbage can (I use rubbermaid Brute cans on wheels) to warm it. You can also add an aquarium heater to the can of water. This is especially effective if you run a small pump at the same time.

Next option:
If you want to keep soft water fish that really demand soft water here is what I would do:
Start with the water that has been treated. (RO membranes do not like high calcium levels)
Run it through reverse osmosis.
Add just enough GH booster to bring the GH to about 3 degrees (or whatever your fish require)
Add just enough potassium bicarbonate to keep the KH pretty close to the GH.
Allow this water to sit overnight in the garbage can and circulate it though some peat moss. This will add the organic acids that many soft water fish like. Add an aquarium heater to the can to warm the water.
 

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Discussion Starter · #13 · (Edited)
I would use the well water before treatment and keep fish that like hard water. Use Prime or other dechlor that locks up ammonia, or get a product that just locks up ammonia.
Keep the outside source protected from the cold and fill a garbage can (I use rubbermaid Brute cans on wheels) to warm it. You can also add an aquarium heater to the can of water. This is especially effective if you run a small pump at the same time.

Next option:
If you want to keep soft water fish that really demand soft water here is what I would do:
Start with the water that has been treated. (RO membranes do not like high calcium levels)
Run it through reverse osmosis.
Add just enough GH booster to bring the GH to about 3 degrees (or whatever your fish require)
Add just enough potassium bicarbonate to keep the KH pretty close to the GH.
Allow this water to sit overnight in the garbage can and circulate it though some peat moss. This will add the organic acids that many soft water fish like. Add an aquarium heater to the can to warm the water.
Just want to verify this. For soft water your suggestion is that I get an RO/DI unit, use my treated (water softener & H2O2) water then add a GH booster, potassium bicarbonate and peat in a garbage can to get it to the right chemistry? I was going to add peat pellets to my canister filter with some Purigen (for clarity) to help with the softening as well.

I was hoping for a soft water community aquarium. We have a pair of angles already and I was hoping to add rams, tetras, etc. My understanding is that plants also prefer softer water. My options are limited for hard water fish. I've had African cichlids and want to steer away from their aggressiveness. Not interested in brackish.

I won't reliably be able to get untreated water in the winter because my only source is an outside faucet/hose. That puts another constraint which would cause me to either use my own treated water in the winter or buy some from my LFS.

If my options are to buy water from my LFS at .50/gal or buy a system I'm sure the system will pay off in no time. I was looking at a MaxCap Standard 90-GPD RO/DI System. Not sure if a flush is necessary or not. $40 more for the manual flush but not sure what that buys me.
 

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Discussion Starter · #14 ·
I pulled the trigger on a Spectrpure Maxcap RO/DI with manual flush. I should be able to make some water with it next weekend and run another round of tests.

Based on Diana's comments I'll then need a GH booster and potassium bicarbonate to increase the hardness as it will be too soft? Please confirm.

Thanks for everyones' help. Good forums.
 

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Plants prefer hard water. Even those adapted to soft water environments prefer hard water, they just get out-competed because they don't prefer it *as much* as hard water adapted species.

From what you described I'd guess the high pH is largely from sulfate produced from the interaction between hydrogen sulfide (the rotten egg smell) and the peroxide you're adding. If it's possible to get water that taps off before your peroxide injector you should be fine with just aging the water as it comes out of the ground. Fill a barrel or bucket, depending how much you need, and let it sit for a day or two (preferably outside so it doesn't smell) so the hydrogen sulfide can evaporate. An airstone will accelerate this, but isn't strictly required.
 

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Also, potassium bicarbonate is a pH booster, so I'd be careful with that. My recommendation for RO water would be to add a buffering mineral like aragonite or oyster shell and do smaller water changes. That is again going to be a hard water system though.

You absolutely don't need to run the DI unit after the RO for your purposes. Replacing resin is an unnecessary expense when you're trying to supplement those minerals after the fact anyway. DI is something reef keepers do when they need to have complete control over their water parameters. It just isn't that essential in a freshwater system, and you end up removing desirable ions too.
 

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I've been testing a new cycling tank and found the PH to be high, likely in the 9+ range. We moved into a new house last year and it has it's own well. There was a strong egg (sulfur) odor so we installed a hydrogen peroxide (H2O2) system in lieu of chlorine. The smell and taste are gone. The problem is that H2O2 causes the water to become very alkaline.

I don't think I have the space to install an RO/DI system which would help to lower but not completely balance the PH. My other option would be to buy the water for every change. Natural PH lowering solutions will not be strong enough and will take time. A water change with high PH will shock the system if I am able to get it neutral.

Does anyone have any suggestions or is buying my neutral RO/DI water my best bet?

Thanks
Hi Johnseye,

Water from a typical well in the Naperville area can run from 13 - 28 gpg (grains per gallon); if my calculations are correct an average about 20 dGH. I would recommend taking your water to a quality aquarium shop and ask them to test PH, dKH, and dGH and get an accurate reading for your specific well.

20 dGH is pretty high for a planted tank and for many tropical fish species.
 

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Discussion Starter · #18 ·
Hi Johnseye,

Water from a typical well in the Naperville area can run from 13 - 28 gpg (grains per gallon); if my calculations are correct an average about 20 dGH. I would recommend taking your water to a quality aquarium shop and ask them to test PH, dKH, and dGH and get an accurate reading for your specific well.

20 dGH is pretty high for a planted tank and for many tropical fish species.
It is high. I'm not sure if dGH is the same as GH, or the difference between gpg and ppm, but the GH goes down to 17.9ppm after going through the softener. 20gpg is equal to 343ppm if I'm correct and I don't believe it's that high. KH stays the same after softening. Once I run the softened water through the RO/DI unit I would suspect my KH to be down to a low level. At that point I'll need to add CaCO3 (Calcium Carbonate) through either a dose or some shells in my canister to get it up to the correct level.

I bought RO/DI because at some point I will setup a reef tank. If I can setup a bypass to just get RO water I will for my freshwater tank.

I think I'm getting a handle on the chemistry. I'll know more after making some RO/DI water.
 

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dGH and GH are just a bit different.

GH is General Hardness, not a unit.
It can be measured in any of several ways, and most of those ways can be converted to each other.

dGH is German degrees of General Hardness, a unit. (there are other degrees of hardness that vary some, in aquariums the German degree of hardness is the most common)

ppm is parts per million, a unit.
This is the same as mg/l.
There are 17.9 ppm in each German degree of hardness.
343 ppm = 19.1 degrees of hardness, and this is hard water. Suitable for Rift Lake Cichlids, and many Live Bearers. Soft water fish generally are at their best with water under 5 degrees GH, though many do just fine up to about 9 degrees. Waterways in most rain forests have about 1-2 degrees GH, and often even lower.

mg/l is milligrams per liter, a unit.
This is the same as ppm.
There are 17.9 mg/l in each German degree of hardness.

gpg is grains per gallon, a unit.
Yes, 20 gpg = 342 or 343 ppm.

-----------------------------------

The most common water softener removes the calcium and magnesium and adds sodium.
A similar machine will add potassium instead.

If the water is otherwise OK (no ammonia or nitrite, low or no nitrate) you could use a blend of softened water with the original water in a ratio that will set the GH suitable for your fish.
 
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