# Will plants acclimatise and sustain at a high PH??



## popeye (21 Oct 2014)

Hi all

My system is running at a solid PH of 8.4 and I have tested everything to find what is pushing it up to no avail so thought I would ask the question if my plants will survive at this PH?

incoming water bang on 7.
Substrate not causing rise, checked over 24h period.
Bogwood in tank.
Tested media over 24h period.
Evan removed magnetic glass cleaners but still no joy.

totally lost!

Thanks


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## Vazkez (21 Oct 2014)

Hi there,

you have very hard water like most of is in UK . To answer your question yes they will survive at least most of them will. They are some which will melt in such a high PH but that's only few of them...
Also some of them can extract the carbonate from water and use it in their advance. For instant Valesia
However if you planing to use CO2 injection your PH will drop. Main is 7.2 during the light period. You can also mix your water with RO but that's just give you more work to do...

To keep it simple yes most of the plants will survive in the PH however you might need to dose Mg depends on your water.

Vazz


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## ceg4048 (21 Oct 2014)

Plants do not care about pH. You need to abandon this worry and instead, worry about keeping your tank clean, as well as not going overboard with light intensity.

Cheers,


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## popeye (21 Oct 2014)

Thanks for that guys that's good to know. I was just concerned due to the amount of or little of CO2 in the wafter at that PH. 
My KH is 4 and GH is 11 if that means anything.


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## Vazkez (21 Oct 2014)

Hmmm how comes that your PH is so high with that KH / GH ???


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## popeye (21 Oct 2014)

thats where i am stumped!


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## ceg4048 (21 Oct 2014)

popeye said:


> Thanks for that guys that's good to know. I was just concerned due to the amount of or little of CO2 in the wafter at that PH.
> My KH is 4 and GH is 11 if that means anything.


This is confusing. The amount of CO2 in the water depends on how much you are injecting, not just on the pH. Is your pH measumennt device correct? You're not giving the right level of information so it's very easy for people to misunderstand and give you inappropriate advice. What exactly are you doing regarding CO2 injection? Are you using gas or liquid carbon? What is the material of the hardscape and gravel? What is the pH coming out of the tap?

Cheers,


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## popeye (21 Oct 2014)

Yes sorry. 

System for a aver a year has been running via a HMA constant drip feed giving a steady PH of 7 and still is! Measurements are taken using a Aquatronica digital PH meter, calibrated more times than ever in the past week. Have crossed checked with Api PH test kit and taken to local fish shop and confirm readings. 
Substrate initally was play sand only 1cm deep.(was discus setup). Has now all been removed and replaced with JBL Mandado and have tested this over a 24h period to no avail still reads 7, so not that. 
Also tested media which is Sera Siporax which doesn't seam to be the culprit either. 
Totally confused what could be pushing it up!

Sorry no pressurised co2 either only recently started liquid dosing co2.


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## ceg4048 (21 Oct 2014)

Thank you.

Liquid Carbon raises the pH.
Gaseous CO2 lowers the pH.

Neither fish nor plants care about pH. They only care WHY the pH is what it is. If the WHY is because of something innocuous then they will not care. If the reason is because of some toxic agent then they will suffer due to the toxic agent, not just because of the pH.

Cheers,


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## popeye (21 Oct 2014)

That's fair enough this issue started before dosing of any kind. Just would of been nice to know what is elevating it.
How does this level of ph effect how the plants consume co2, as am i right that there is less co2 present in the water the higher the ph?

Thanks for your help!


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## ceg4048 (21 Oct 2014)

popeye said:


> am i right that there is less co2 present in the water the higher the ph?


No. This is not only wrong, it's very wrong because it is like using a cart to drive a horse.
Adding CO2 to water causes a chemical reaction between a small fraction of the dissolved CO2 (between 1/1000th to 1/600th) and the Hydrogen ions in the water. This reaction creates a small amount of a weak acid called Carbonic acid. This is the acid responsible for lowering the pH of the water. This acid is only a small contribution of total amount of acids in the water which affects the final pH that you measure. Unfortunately, people read the pH/KH/CO2 charts and assume that it applies to all the CO2 dissolved in the water.

When the alkalinity of the water is high, it immediately buffers the Carbonic acid and prevents the pH from falling. So people automatically falsely assume that because the pH is high it means there is less CO2 in the water, but all it means is that the Carbonic acid cannot overcome the strong buffers in the water. The CO2 is still there but it's presence is hidden by the alkalinity and therefore hidden by the lack of movement of the pH.

When the alkalinity of the water is low then there are fewer buffers in the water so the same amount of Carbonic acid produced by the same amount of CO2 dissolved in the water now becomes more obvious as it now has the ability to overcome the weak buffering of the water and so the pH falls more readily.

A glass of vinegar water, or a tank, or even a great lake all have exactly the same amount of CO2 dissolved in them but their pH will all be different because there will be different level of alkaline buffers in each. The solubility of Co2 in water is only ever dependent on Pressure, temperature and Sodium Chloride (NaCl) content.

So you cannot determine the CO2 content of water just by reading the pH, however, we frequently measure the pH at various intervals during the CO2 injection period and the DIFFERENCE in pH will give you an indication of how much CO2 is dissolved.

Cheers,


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## popeye (22 Oct 2014)

great reply thanks for that that makes me feel a little at ease. having a higher PH should i be doing anything different to those with a lower PH? should i still dose my system in the same way and the same recommended amount of liquid fert and liquid CO2?
Just want to succeed!

Thanks again ceg4048


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## ceg4048 (22 Oct 2014)

As I mentioned, pH is completely irrelevant within this context.
Sometimes you need to worry about pH, but that is in very special circumstances. In most cases the pH is measured in order to use the numerical value as a tool.

So for example, people who inject CO2 need to understand that the amount of CO2 injected is related to the amount that the pH changes over the course of the day. In that circumstance the pH is an important number because that relationship helps to diagnose problems with the injection techniques.

In other case, the pH is important number because certain agents in the water change their toxicity to fauna as a function of the water's pH. So for example, some people use heavy doses of ammonium salts as their choice for Nitrogen fertilization. When ammonia is dissolved in water there is an equilibrium phenomenon that occurs where a certain percentage of the ion exists as highly toxic ammonia (NH3) while the remainder exists as a much less toxic ammonium  (NH4). At pH below 7 the less toxic NH4 is much more abundant, however, above pH 7 the NH4 converts to a greater percentage of highly toxic NH3. So this can be a source of problems if, for some reason the pH rises, but again the damage is being don by the toxic agent NH3, not by the pH.

Another typical example of this is if a fish dies undetected in the tank. if the natural pH of the water is low then as the corpse decays ammonia is released and stays as the less toxic NH4, but if the pH were above 7 then the decay would potentially have a much more serious impact on the other fish.

So, pH is something to be aware of but it's not something to be obsessive over. If you are using source water with a neutral pH, and if the tank water rises then it can only happen as a result of alkaline substances getting dissolved into the water from gravel, hardscape or filter media, or from products being added. Typically, the pH should fall because the tank normally produces acidic substances. So certainly it should be investigated  as time allows but there is no difference in procedures or techniques that must be applied.

So there is nothing special to do. Large and frequent water changes are advisable when CO2 is being enriched, so the addition of liquid carbon means that you need to implement a more rigorous cleanliness policy because of the additional organic waste being produced by the plants/ A 50% weekly change is not unreasonable. Organic waste is what kills fish, not pH.

Cheers,


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## popeye (24 Oct 2014)

Hi Ceg

Following on from this what's your view of using peat pellets on a planted system?

Cheers


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## ceg4048 (24 Oct 2014)

Well, again, peat is used in certain situations in order to reduce the pH of the sediment. That's one of the reasons it became popular. For terrestrial plants this may have some relevance, but for our purposes it's not that important. Check the post http://ukaps.org/forum/threads/sphagnum-moss-or-peat.33722/#post-359465

Cheers,


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## popeye (25 Oct 2014)

Thanks mate. Today I went out and bought a brand new PH test kit and it is saying tank is bang on 7! So looks like my Aquatronica ph probs days are numbered and on further inspection the other test kit I used has expired. :s

So this now makes more sense of my low KH of 4.


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