# NYC acidic water - raising ph with crushed corals?



## Greendot (Jun 3, 2012)

Hey

My ph is around 6.8. I was told by a local shrimp and snail breeder that he adds crushed corals to his tanks to raise the ph. 

Any thoughts on that? Any issues with me doing that ?


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## mistergreen (Mar 3, 2007)

Yes, any calcium carbonate source will work in your soft, slightly acidic water.


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## Greendot (Jun 3, 2012)

And how do I go about doing that? I just sprinkle some and forget about it? Or do I put it in a bag or something and put it in to be removed later on?


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## mistergreen (Mar 3, 2007)

Any way you want. Generally you don't want to remove it so when you do a water change the calcium carbonate will balance out the new water.


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## jatcar95 (Oct 30, 2019)

Does crushed coral affect PH? I thought it was generally to increase GH. If you're just looking to increase PH, you could also add something like baking soda, although won't increase the water hardness. If you also have soft water, I'd recommend taking a look at this thread: https://www.aquaticplantcentral.com/forumapc/el-natural/144571-increasing-water-hardness-recipe.html


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## mistergreen (Mar 3, 2007)

jatcar95 said:


> Does crushed coral affect PH? I thought it was generally to increase GH. If you're just looking to increase PH, you could also add something like baking soda, although won't increase the water hardness. If you also have soft water, I'd recommend taking a look at this thread: https://www.aquaticplantcentral.com/forumapc/el-natural/144571-increasing-water-hardness-recipe.html


It will increase pH, kH, GH.


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## dwalstad (Apr 14, 2006)

Crushed coral is CaCO3 (calcium carbonate). It will very slowly dissolve into Ca and bicarbonates. Both are good for tank. Ca will increase the GH. The bicarbonates will increase both the KH and the pH.

Plant requirement for water Ca is absolutely vital. Adding the crushed coral, in my opinion, trumps any possible problems with a mild pH increase.

If you are running a filter, you could add a small bag of crushed coral to the filter. Or scatter _small_ pieces of crushed coral onto the substrate.

Testing and learning about GH, KH, and pH are important since you have NYC softwater. Monitoring GH will give you feedback as to whether the coral is dissolving fast enough. If it's not getting GH above 4 in a reasonable amount of time and plants aren't doing well, you may have to consider other options.


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## Chris. (Dec 22, 2008)

jatcar95 said:


> Does crushed coral affect PH? I thought it was generally to increase GH. If you're just looking to increase PH, you could also add something like baking soda, although won't increase the water hardness. If you also have soft water, I'd recommend taking a look at this thread: https://www.aquaticplantcentral.com/forumapc/el-natural/144571-increasing-water-hardness-recipe.html


It will bring ph to around 7.2 and keep it there.


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## johnwesley0 (Feb 23, 2021)

I live in Brooklyn and have the same problem. I'm convinced that the acidification process is what kept crashing the cycle in my next to last tank. A nice lump of fused seashells and sediment I'd found on the beach at the Gulf of Eilat nearly a half-century ago did the trick; I just placed it in the tank and the ph rose steadily over the space of three or four days from 6.5 and has held at the 7.2 level for about six weeks. I would avoid bicarbonate of soda unless you want to continually add it on a regular basis. You want something that will act as a buffer, not just an additive. A good buffer is supposed to raise alkalinity until the ph reaches neutral and then stops interacting with the water.


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## dwalstad (Apr 14, 2006)

The main goal is to add calcium to the water. Plants need it in the water or they will die. Shrimp need it for their shells and to molt.

Sea shells (CaCO3) provides calcium as they dissolve. The fact that they increase the pH is not nearly as important.

Baking soda (NaHCO3) has no calcium.


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## johnwesley0 (Feb 23, 2021)

Does the calcium source have to remain in the tank indefinitely, assuming there's no need for water changes? I ask because the ph still seems to be rising ever so slightly since I introduced my sea shell rock. I'm not accustomed to my liquid tests resulting in such lovely shades of blue, so I do worry, how high is too high?


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## dwalstad (Apr 14, 2006)

Complex question, and frankly, I cannot answer it without more information. What is the GH? How are the plants doing?

The higher pH could be from plants growing better. (Their photosynthesis increases the pH as they pull CO2 out of the water.) And if your plants can use bicarbonates, then it won't matter how much CaCO3 dissolves. If you have floating plants, it won't matter to them.

CaCO3 will increase the pH. That is why my recipe contains CaCl2, which will not change pH. It also contains Mg and K, which is probably deficient in NYC water and needed by your plants.

The commercial product "Wonder Shells" apparently won't increase pH, and has worked well according to JatCar95. Here is his very helpful thread on increasing water hardness with the Wonder Shells. I suspect the manufacturers have added other plant nutrients like Mg and K to this product.

For you, what's important is how are the plants doing with the shells in the water? I would leave them in for awhile despite the pH increase. A photo of your tank would help.


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## johnwesley0 (Feb 23, 2021)

Unfortunately, I stopped measuring GH when I purchased the API master kit. I found the strips I had been using relatively useless. Apparently, my GH was so low that it didn't even register on the strips.

I'm so glad you asked to see my tank! This is a snapshot I just took a moment ago. It's looking down into a ten gallon Chinese bowl that probably has about seven gallons of water at the moment. The all gravel substrate covers a diameter of approx. 11 inches. The anubias are five years old and have survived several tank set ups. But, I'm assuming most of the nutrients are being vacuumed up by the four sticks of lucky bamboo roots which are covered by an inch of substrate and are relative newcomers. My "sea shell rock" is at 9 o'clock.


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## johnwesley0 (Feb 23, 2021)

deleted to keep thread tidy.


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## Pablos (Mar 12, 2021)

As far as I'm aware crushed coral is not only Ca

https://www.ldeo.columbia.edu/~peter/site/Papers_files/Hathorne.etal.2013.pdf


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## dwalstad (Apr 14, 2006)

Granted, crushed coral may have traces of other elements besides Ca but not enough to sustain plant growth. Crushed coral is mainly CaCO3. "Coral skeletons are made of aragonite, a form of calcium carbonate. To grow up toward sunlight, corals construct a framework of aragonite crystals."

Pablo's scientific article has lumped Ca and Mg together, so it does not tell us how much Mg coral provides. I suspect it's not that much. Also, coral doesn't have K, a major nutrient.

That said, the bottom line is how well johnwesley's plants do. Since he's had the Anubias for 5 years, he must be doing something right! Bamboo is a nice and smart addition for this beautiful bowl.


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## Pablos (Mar 12, 2021)

The ratio in the crush coral is 1000:4 Ca:Mg based on that article, so as you said it would not be enough for the plants.

I’m using crushed coral in my tank, as tap my tap water is KH 2.5 and GH less than 4. If I compare my Anubias with John’s, I can ensure you that coral is not a magic formula. His Anubias are presenting a way better then mine.


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## dwalstad (Apr 14, 2006)

Thanks for information, especially about Ca:Mg ratio of only 1000:4. Very helpful! 

Anubias are slow growers, so I think it would take awhile to see the effect with them. The Amazon swordplant is a really good indicator; it will turn to mush without Ca in the water.

I think we're still down to my recipe (my book, page 87), which I think is optimal, but it requires some effort. My tapwater has GH = 2, very low. I have been following the recipe now for about a year. I've kept GH above 5 and all fish, plants, and shrimp are doing well. One day, though, the guppies weren't looking good and one young female died. Unacceptable! Checked nitrogen and all N parameters zero, but the pH was very acidic, lower than 6. I added NaHCO3 to all my tanks, 1-2 tsp/gal, something that I had neglected in the past when I was so focused on Ca.

Still processing the idea of Wonder Shells, which looks like an easy solution and worked very well for one person.


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## Pablos (Mar 12, 2021)

Wouldn’t backing soda increase pH, which basically decrease dissolving seashells or crushed coral?

Just asking what would be the best way to buffer water. My tap water is GH 3.6dH and KH 2.5. I’m using mentioned crushed coral. On top of it seachem equilibrium and Epsom salt after each water change to add an extra +1 GH.

With crushed coral, additional Mg and seachem, my GH is maintained on the 7dH level.

Is there a way I can buy your book for kindle?


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## hoppycalif (Apr 7, 2005)

Pablos said:


> ..........
> 
> Is there a way I can buy your book for kindle?


https://www.amazon.com/Ecology-Plan...&s=books&sprefix=walstad,undefined,235&sr=1-1


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## johnwesley0 (Feb 23, 2021)

dwalstad said:


> Thanks for information, especially about Ca:Mg ratio of only 1000:4. Very helpful!
> 
> Anubias are slow growers, so I think it would take awhile to see the effect with them. The Amazon swordplant is a really good indicator; it will turn to mush without Ca in the water.
> 
> ...


My sea shell rock, pictured upstream, very gradually increased my ph over the space of a month from 6.5 to 7.5. I thought it was buffering the water (and, maybe it was.) But, I didn't want to take any chances of the water becoming _too_ alkaline and removed it about a week ago.

Correct me if I'm wrong, but I think I remember reading in one of your articles that the nitrogen cycle itself tends to lower ph over time. Did I get that right?

Oh, and a bonus question: Where do lucky bamboo get their CO2? From the air or from the water?


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## dwalstad (Apr 14, 2006)

Pablos said:


> Wouldn't backing soda increase pH, which basically decrease dissolving seashells or crushed coral?
> 
> Just asking what would be the best way to buffer water. My tap water is GH 3.6dH and KH 2.5. I'm using mentioned crushed coral. On top of it seachem equilibrium and Epsom salt after each water change to add an extra +1 GH.
> 
> ...


Besides Amazon and other Internet sites, you can buy my book (eBook, PDF, and hardcopy) from printers/distributors at Baker and Taylor. (Thanks for opportunity to shamelessly promote my book.)

Yes, baking soda will increase the pH, but it depends on dose. I really needed to get pH up. Next day, pH was about 6.8. I added a little more. Guppies and shrimp come first!

I would recommend against what you are adding to your tank. The crushed coral is fine, but you are drowning your tank with sulfate salts. Seachem Equilibrium is all sulfate salts. (Check the ingredient list.) Then, you are adding Epsom salts which is MgSO4, another sulfate salt.

Explanation: You don't want to add too many sulfates, because anaerobic bacteria (sulfate-reducers) convert them to toxic H2S (my book, p. 67). In high tech tanks with gravel substrates, Equilibrium might work okay if there's not a lot of accumulated organic matter. But in a soil-based tank, which is so rich in organic matter, those sulfates will easily become H2S and kill/injure/inhibit rooted plants. (That's why my recipe uses CaCl2, which doesn't increase pH and doesn't have sulfate's potential to do damage.)

Natural hardwater is composed of mostly chlorides, sulfates, and bicarbonates. Adding pure sulfates is not only unnatural but in my opinion unsuitable for soil-based tanks.


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## Pablos (Mar 12, 2021)

hoppycalif said:


> https://www.amazon.com/Ecology-Plan...&s=books&sprefix=walstad,undefined,235&sr=1-1


Diana, apologize my ignorance, I didn't realized it's you ... of course I do have your book. I guess I need to read it third time 

Going back to the subject. You said ' Instead of the above procedure, you can just add crushed sea shells or oyster grit to the filter or substrate.'. However crushed coral would only provide Ca, but would not provide Mg (or very minimal based on the previous paper) neither bicarbonate. is it really substitutes solution?


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## jatcar95 (Oct 30, 2019)

dwalstad said:


> Seachem Equilibrium is all sulfate salts...You don't want to add too many sulfates, because anaerobic bacteria (sulfate-reducers) convert them to toxic H2S (my book, p. 67)...in a soil-based tank, which is so rich in organic matter, those sulfates will easily become H2S and kill/injure/inhibit rooted plants.


I am fairly convinced this was the primary cause of the collapse of my previous tank. I was using Equilibrium frequently and ended up with dead plants and a lot of smelly substrate (my gravel cap was a tad too thick as well, but I don't believe that was the main issue).

I've been using Ms. Walstad's recipe on my current tank, and more recently, wonder shells. Both have worked fantastically for me. The plants that (barely) survived the first tank are thriving in the new one, including a couple very happy swords.

Wonder shells are great if you want to increase hardness, but they don't affect pH or kH. To bring that up, I've been using Seachem Alkaline Buffer (which is probably just baking soda with fancy packaging).


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## dwalstad (Apr 14, 2006)

Thanks for chiming in. There are other hobbyists that noticed an improvement when they switched. Excessive sulfates are deadly.

Crushed coral isn't perfect, but it does no harm and might help in a borderline situation. (Unlike sulfates, it won't harm your plants or kill your bottom-dwelling fish.) Optimal thing, though, is to follow my recipe or try out the Wonder Shells.


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## Pablos (Mar 12, 2021)

Is there a define an acceptable sulfates level in a tank?

As Christian posted great algea imbalance article, an expected ratio Ca:Mg should be 1:4
https://www.aquaticplantcentral.com...thod-controlled-imbalances-discussion-22.html

Neither crushed coral would help there (too less magnesium) nor Epsom salt, as it would add too much sulfates. Wouldn't Magnesium nitrate be the best solution?


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## dwalstad (Apr 14, 2006)

I use approximate levels, doses, and ratios. As long as there's enough of each nutrient, let the plant decide how much to take up. There's no need to fine-tune ratios and doses unless you're running a scientific lab. And the idea that people can control algae by tweaking nutrient ratios is "far-fetched," to put it kindly.


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## Pablos (Mar 12, 2021)

Interesting option about the ratio with an algae control. I'm not really looking for the perfect golden ratio. For me the more important is to provide enough nutrients for my plants and my discus fish.

My tap water is desalinated salt water ... the process is very similar to the RO, so water is very soft: TDS =70ppm, Ca = 24ppm, Mg 1ppm, K = 0ppm

I thought by adding crashed corals, Epsom salt and seachem equilibrium, I'm helping .. but you're saying that with too many sulfates, I might do opposite and might kill plants or fish.

I was trying to find how much sulfates is too much and found some paper, which says 250ppm level might be dangerous (See attached file)

Unfortunately Seachem doesn't precisely say what are ingredients: 
https://seachem.zendesk.com/hc/en-u...uce-any-Chlorides-or-Sulfates-into-the-water-

but at least we know it's from sulfate.

Regarding GH / crashed coral.

My tap GH is 3.6, then I'm adding + 1.0 from equilibrium + 0.5 from Espom salt + something from crash coral. At the end my readings are 7 dH.

Based on my calculation I'm adding weekly ~10 ppm SO4. Should I really be concern about sulfates level? Should I stop with equilibrium and magnesium sulfate?


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