Jump to content
Sign in to follow this  
daveron

Ph always rising - but why ?

Recommended Posts

daveron

Hello,

So the problem is, that my pH is always rising and settling in the range of around 6.8, but I fail to understand why and I hope you will clarify the problem for me. Let's get into details:

I am running inert substrate tanks, which have the following parameters: pH 6.7-6.8, GH 5-6, KH 0-1, TDS ~125.

My routine is that I do weekly water changes of around 20%. The water for changes is RO water + salty shrimp GH+ + Azoo Triple Black Water (which is basically a tannins and humic acids extract)+ Azoo Ph Lower, and I usually adjust the pH to around 6.0-6.2 as I want to keep it acidic, but the pH just won't go down lower than 6.7(to be exact - If I would add peat, or a lot of those acids, then sure it would go down lower, but after some time it always comes to it's usual 6.8 range). I also adjust the pH of the top-up water, which is RO + Triple Black Water.

As I am adding a lot of acids into the water I thought the pH should stay acidic, unless there is something that absorbs those acids.

So I did a test - I have prepared my usual bucket of water, re-mineralised it and adjusted pH to below 6.0 and let the bucket be. After around 24 hours I have measured the pH of the water in the bucket and, the pH was back at around 6.6. So it raised a lot. Once again I lowered the pH to below 6.0 using Triple Black Water only, and after another 48 hours the pH was again 6.8.

So why is the pH rising ? I understand that with kH 0 there is nothing to buffer the water, but since I am adding acids into the water and there is nothing that could absorb them what causes the pH to raise ?

Thanks !

Share this post


Link to post
Share on other sites
Zoidburg

It's probably best to stay away from products that raise or lower the pH and get a buffering substrate that can keep the pH lower.

 

Is there a reason you want it lower?

Share this post


Link to post
Share on other sites
revolutionhope

I'm not good with chemistry but I think the pH is rising because there is co2 which is in the form of carbonic acid which is being off-gassed hence the pH rising to its equilibrium which seems to be 6.8. Which is fine for most softwater shrimp I should think?



Edit- doesn't answer the question as to why the pH keeps rising after adding more acid on subsequent occasions though I'm sorry!

Share this post


Link to post
Share on other sites
daveron

Thanks for your responses.

Well the shrimp are doing fine - especially mischlings which are breeding like crazy, however I wanted to lower the pH to suit TB preferences better, and possibly get more breeding.

I am also genuinely interested as to what is causing such pH behaviour.

 

Share this post


Link to post
Share on other sites
Zoidburg

I would say that stability is more important than having exact parameters. Besides, if they are thriving just fine in it the way it is, why change it?

 

What I know for sure is that without KH, the pH can swing and be unstable. Without a buffering substrate, the pH is likely to climb. If you want lower pH, then invest in buffering substrate.

 

Make sure that there's nothing in the aquarium that could cause the pH to rise (such as rocksthat are not inert) and possibly look into driftwood and leaves. Maybe even use peat moss to try and lower the pH naturally.

 

Using the pH down chemicals doesn't result in stable parameters, and I don't think they are meant to. It's more of a temporary fix, if you will, and may cause more stress than needed on the inhabitants.

BTW, if you can get something like the Marina Hang On Breeder Box that uses a small pump to circulate water into the box from the tank, and you modify it to be safe for shrimp, you could put a small layer of buffering substrate into the breeder box. In this way, you wont have to replace the substrate in your tank, but you will still have something to buffer the pH down.

 

The only caution here is that some substrates *will* release ammonia, so you may need to "cycle" the substrate first prior to use... unless you can find one (i.e. SL-Aqua Soil or?) that doesn't release ammonia (or not much at all) that can be used asap.

Share this post


Link to post
Share on other sites
daveron

Pretty awesome tip with that Marina Breeder Box.

I already did something like that in my TB tank, but instead used one basket in my canister filter. I placed around 1kg of H.E.L.P Shrimp Soil in it. Unfortunately It hardly buffered the water any lower. Maybe 1kg is not enough , to buffer 30L tank... 

As for ammonia leaching I assumed that only soils like ADA Amazonia which are full of fertilizers will release ammonia, or is that wrong ?

On the other hand peat gets the pH down easily, but you really need to add very small amounts gradually to avoid pH plummeting down, which is not something you can do easily in a canister.

Share this post


Link to post
Share on other sites
Zoidburg

I don't know if any soils besides ADA Amazonia leach ammonia.

I've heard of people putting peat in a sock near the filter outlet, and others who use peat in a bucket prior to doing water changes.

Share this post


Link to post
Share on other sites
Brentwillmers
On 09/12/2016 at 9:12 AM, revolutionhope said:

I'm not good with chemistry but I think the pH is rising because there is co2 which is in the form of carbonic acid which is being off-gassed hence the pH rising to its equilibrium which seems to be 6.8. Which is fine for most softwater shrimp I should think?

 


Edit- doesn't answer the question as to why the pH keeps rising after adding more acid on subsequent occasions though I'm sorry!
 

 

Sorry I know it's an old thread. But it's pretty spot on. I could go into the full reasoning on it. But carbonic acid is something that gets depleated quickly. A situation is in planted tanks with very touchy plants battle with on a daily basis without the addition of compressed Co2 infusion. Using fulvic acids would help to stabilize PH a bit better. But it has an expiration date and will get depleted too eventually. So a buffering substrate is a far more reliable method (also contains fulvic acids) Another thing why unstable PH is a danger on itself is it being logarithmic so acids or alkaline levels when fluctuating can poison your waters very quickly. A PH of 6 is 10 times more acidic than a PH of 7 and a PH of 5 is a thousand times more acidic than 7. 

You trying to lower your PH to 6.0-6.2 from 6.8 keep in mind to do the change very slowly around 0.2 value per 24hour period if possible to avoid the hash change for shrimp. 

Just my late 2c worth?

 

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Similar Content

    • jayc
      By jayc
      Understanding toxicity impacts between pH level and Ammonia.
      How does pH affect the toxicity of ammonia?
       

      Table 1 - the Nitrification and Ammonification process.
       
      The Ammonia reading you get from test kits is actually the sum of Total Ammonia - which is made up of Ammonia NH3 + Ammonium NH4.
      At low levels of pH (lower than 6.0), ammonification occurs. Remember, pH is an inverse count of Hydrogen (H). At low pH, you have more Hydrogen. At high pH, you have less. At these low levels of pH (high acidity), the ammonia NH3 'absorbs' (for lack of a better word), an extra Hydrogen ion -> becoming NH4 or ammonium.
      The reason Ammonium is less toxic to fish and shrimp is because NH4 with that added Hydrogen H ion is now less permeable to the gills of fish & shrimp. NH4 is also excreted across the gills via a carrier mediated process in exchange for sodium Na+.
      Ammonia toxicity is also influenced by temperature:
      The lower the temperature the less toxic it becomes. Or to put it another way - NH3 toxicity increases with temperature and pH.
          Percent NH3 of total ammonia Temp  pH 6.5 pH 7.0 pH 7.5 pH 8.0 pH 8.5 20C / 68F 0.13 0.40 1.24 8.82 11.2
      25C / 77F 0.18 0.57 1.77 5.38 15.3
      28C / 82F 0.22 0.70 2.17 6.56 18.2
      30C / 86F 0.26 0.80 2.48 7.46 20.3
      Table 2. Un-ionized NH3 as a percent of total ammonia (by temperature and pH).
       
      Assuming a temp of 28C and a pH of 7.0 - if 5ppm of ammonia is present this results in only .03 ppm ammonia.
      However, in a Tanganyikan Cichlids tank with a pH of 9.0, that has a Total Ammonia of 5 ppm, your ammonia level is 2.06 ppm! This now become toxic for the fish.
       
      But, at a pH of 6.0, and 10 ppm of Total Ammonia, the ammonia is only .007 ppm. Even though we have MORE ammonia.
      So be cautious when performing water changes in a low pH tank, as the low pH has an adverse affect on the nitrifying bacteria that converts ammonia to nitrite.  Because of the acidity these bacteria populations can drop so low that any change in alkalinity can cause the Total Ammonia reading to rise quickly.  While the pH stays low the Total Ammonia reading is nearly all ammonium, but if you do a water change or add an alkalinity buffer to the system, the ammonium can be quickly converted to ammonia, potentially causing ammonia poisoning.
      It is good to note here that, as per the very top picture (table1) ... nitrifying bacteria that convert ammonia NH3 to Nitrate (NO3) does NOT convert Ammonium NH4 to a less toxic form. The bacteria isn't present in sufficient amounts in such low pH environments to process it. Ammonium NH4 is ever present in a low pH tank that has living creatures in it. NH4 is in there ready to be converted into NH3 at the first sign of added alkalinity during water changes. Hence, why we always tell you to match water parameters and add it into the tank slowly (drip it in if you can), don't dump in buckets of new water all at once.
      So in summary, the combination of low pH (<6) and cool temperatures that the shrimp live in can mean that high ammonia levels are not toxic to them. But be careful !!! Any change in the pH buffer that increases alkalinity will cause the toxic ammonia to immediately convert from NH4 to NH3.
       
      There you go. Hopefully that is a more precise explanation to aid your understanding. 
      The ideal spot to be is just above 6.1 to 6.5, where bacteria still function, and ammonia is less toxic. Along with the cool temperatures some shrimp (or fish) live in,  is the best environment to be in to minimise ammonia poisoning.
      I wonder how many times our shrimp die in hot temps, (say due to hot weather ... maybe even a broken heater) not because of the heat, but because our low pH tanks have not enough functioning bacteria to cope with the sudden change in toxic NH3 ammonia due to the rise in temps??? Food for thought.
    • macjeff
      By macjeff
      I have had a 20 gallon RCS tank for 3 years now.  I have moss balls and some JAVA moss, drift wood, and mineral rocks.
      Only RCS in the tank and some soft shell snails I have in there I breed for my fresh water puffer fish in another tank,.
      My issue is that the shrimp live 1-2 years and they breed just fine but I never see babies.  I see plenty of eggs but never babies.  (Well 1 or 2 a month maybe but they disappear)
      The adults keep going just fine until they die off of old age or something else.
      I keep about 100 shrimp in the tank and have to replenish 50 every 6 months about.
      Water Temp I keep about neutral. 
      PH- 7- 7.2
      I use distilled water or sometimes Reverse Osmosis water because our tap water goes through a water softener which puts a LOT of salt in it which makes TDS very high so I try not to use tap water at all.   
      I feed every 2 days with Azoo or other good food and not much.  Its all gone by the time I feed again.
      I do add some powder food for the babies and a shrimp bacteria powder (just started that about 6 months ago but has not helped or hurt)
      Someone told me due to the distilled water my issue is LOW TDS.  So I bought TWO different meters.  I tested the distilled water and its about zero which is correct.  I then tested my water and its about 700.   I do top offs and just did a 20% water change last weekend with distilled water.
      So is that the issue?  Should I pull out the mineral rocks?
      I am thinking tonight to take about 8 gallons of water and drain the tank down about 40% and then fill with the distilled water.   I can repeat the process in a week and once I get the TDS under 150 I can add a little shrimp mineral to get it to the 200 range.   The reason I am saying that is the TDS could be bad TDS and not the minerals they needs.  I ordered some Salty Shrimp Mineral which I heard was good.
      Should I just give up?
       
      Jeff
    • puddlejumper388
      By puddlejumper388
      Hi everyone, I have spent some time searching (unsuccessfully!) for any threads set up to address how to naturally and chemically treat the more important water parameters. Obviously I'm not talking about temp, but the PH, TDS, KH and GH levels are the ones I'm most interested in. Now I'm country based so the only water I've got access to is R/W and bore (perfectly drinkable from the pump itself, no brackishness) which I have used for 4 of my 6 tanks (tropical and a few lower grade cherries). But I want to better hone in the water condition as best I can so any tricks to raise lower the above parameters naturally or if need be chemically. Or if anyone knows/finds a link, anything will be appreciated.
      Had put this in the pinned "Shrimps 101" but will try to delete it as it's probably better as a separate post.
      Being rural makes water choice difficult and some of the values I've tested are way out, hence why I'm seeking advice.
      Cheers all.
       
    • revolutionhope
      By revolutionhope
      Hey SKF peoples,
      I'm just mixing up my RO water with a combination of GH+ and GH/KH+ to keep tiger shrimps in. And I thought I'd share my experience, I gradually added the minerals and measured pH along the way and I thought I'd share the results.
      I note that the pH may change overnight after letting stand but I have been running a pump in the water to mix it well and aerate it so I doubt there will actually be any measurable shift.
      As you can see by the results, the GH/KH+ pushed up the pH a LOT! Does anyone else have this experience? I have achieved my desired water parameters in terms of ppm and GH/KH however the pH is unreal.. and this is not the first time this has happened to me either. However t is the first time I have taken the effort to document the fact.
      I'm planning on experimenting with adding a very shallow layer of the cal aqua labs black earth premium and monitoring the pH over the course of days.. expecting it to slowly drop...
      Any input is 100% welcome!
      love n peace
      will
      PS the initial drop in pH after adding the first lot of GH+ I understand can be explained (as I have read elsewhere) that when attempting to measure the pH of RO water using a pH meter the device can not accurately produce any result due to the lack of ions/conductivity in the water.
      27/05/2016 EC meter  HM  TDS-3 pH meter pH APIkit      KH        GH At time of water mixing EC0  ppm0         fresh RO     6.6       after adding 50ppm GH+     6.3       after adding 30ppm GH/KH     7       after adding 25ppm GH/KH     7.5       after adding 45ppm GH/KH EC300   8.3       after adding 17ppm GH/KH EC333  ppm175 8.3 7.8 3 8
    • revolutionhope
      By revolutionhope
      Hi SKF!
      I'm hoping to get some advice and opinions on managing pH for a tank with cherries and bee shrimps.
      My pH is measuring around 5.4 and I'm concerned it may continue to drop over time to unacceptable levels even for bee shrimps. Currently there is only CRS in the tank but I want to add some neos soon.
      Firstly some background detail - I have a tank with a modest amount of cal aqua labs black earth premium as per the manufacturer's advice. I use RO/DI water (I changed cartridge recently and TDS of RO is zero) with SS GH+. I keep up with regular WC and the TDS is about 140ppm at last check. The tank is heavily planted, has quite a few pieces of driftwood here and there and also some catappa/IAL. There is oodles and oodles of filtration including canister and air driven sponges, and the stocking rate is low-medium. There is some benibachi fulvic grains in the canister (although these fulvic grains are roughly 6 months old and should be close to expiring now; however I will still remove these fulvic grains when I get around to doing some maintenance on the canister however). The shrimp are quite happy and new ones are regularly getting berried.
      Anyway, so aside from removing the fulvic grains and possibly removing the indian almond leaf, and maybe some of the larger driftwood which may help to prevent the gradual acidification that is going on. I am wondering if anyone has experience using small amounts of aragonite or similar to help buffer the tanks. If anyone has any other suggestion or opinion it will be greatly appreciated. I don't fancy that cherry shrimps will breed very well in pH 5.4 or less and I really do want to keep some different coloured shrimps in this setup!
      I will be most grateful for any input :-)
      love n peace
      will
      -edit- I should add that it's true that as a last resort if it really comes to it then I could remove some of the substrate but I don't want to pollute the water in this way if I can avoid it..
  • Must Read SKF Articles

  • Join Our Community!

    Register today, ask questions and share your shrimp and fish tank experiences with us!

  • Posts

    • sdlTBfanUK
      Catappa leaves are Indian almond leaves, as you say. Biofilm gows on the leaf surface as well which the shrimp love to eat so it is worth getting some and I imagine they are readily available! Your tap water may be very good in your part of the world, it is probably less messed about with I imagine than most of the world. It sounds like you ae having great success so I recommend you carry on as is and don't use anything you aren't already using, especially  chemical wise at this stage. I think the 20% water change each week should slowly bring the PH/KH down to better parameters for caridina shrimp but if they have survived 2 weeks they are doing ok as they are and should be ok, just put the new water in very slowly, over many hours! Hopefully this will counter anything that may be raising the PH/KH and it may fluctuate over the week but it will be so slow it won't harm the shrimp whilst keeping those figures from raising too high! We may need to revisit it later if shrimp start dying, but as it is doing so well don't try and change things too much or unnecessarily and the water changes should reduce the figures slowly and stop any extremes of parameters over times. The caridina are much more difficult to keep than the neocaridina but I understand wanting to keep the caridina. The setup you have would ideally suit neocaridina better but hopefully this will work out long term for the caridina with minimal extra effort! Simon
    • Ricky ng
      Hey Simon, Thanks a lot to stop by and for all the useful information that you gave such a blessing to have you in this forum. I put 3 pine cone first to see how it goes lol i dont know if i can find that leaves but i think i can get the catappa leaves i think they all just the same.. my question is that since i also have purigen in my filter i believe it will absorb all the tannin so i dont know if the leaves still can reduce the ph.. what about seachem acid buffer or ADA soft water? Well the neos want keep breeding black bee and red bee also thriving for quite some time when i usr tap water plus seachem prime.. low grade prl and tiger fancy low grade has been there for just a month maybe but bb and panda just 2 weeks.. but i will try to do your suggestion 20% RO mineralize water changes..  Mosquito i think is a great idea mate.. and thanks a lot again for all the information that you gave.. may GOD bless you mate..
    • sdlTBfanUK
      Wow, what a great tank you have there! Usually a soil substrate s used with Caridina shrimp as that buffers the PH to ideal for te shrimp, but clearly you aren't going to re-do the tank at this stage. Adding Indian almond leaves can help the PH a little and you can put those at the back behind the scaping so they don't affect the look. RO water will have a Lower PH (usually 6 or lower) and a KH of 0 so water changes can bring them down so, I would maybe do 20% RO (mineralised) water change a week to start off and see where that gets you in a month - add new water very gradually, a dripper is best! The dragon stone may be increasing the PH/KH but if the 20% water change works and is manageable then maybe continue with that indefinitely - obviously you aren't going to remove the stone, that would be madness in such a beautiful setup?  If the shrimps are suriving then I wouldn't worry too much and I assume you acclimated them well. How long have the shrimp been in the tank? With RO water you will need to add minerals which would be GH+ for the caridina shrimps. Your KH is a bit high for Caridina normally so don't use GH/KH+ as that will also affect the KH. Tap water rarely works with caridina! As for fish, I think it would be risky with Harlequin rasbora (they grow quite big for a shrimp tank), especially if the shrimp start breeding, but chilli/mosquito/dwarf spotted fasbora should be fine as they are no bigger than an adult shrimp. I keep neon tetra and ember tetra with some red cherry shrimp but it is very densely planted so shrimps can (and do) hide a lot but I still expect the fish must get SOME baby shrimps? Even the micro rasbora may eat some new born shrimp of coarse. The biggest pointer though is if it is working don't try to fix it, I had caridina in PH the same as yours and they were fine even though it's not perfect for them! It can cause more problems changing things than it solves as many have found out........... just do as you are doing with the water changes of 20% RO mineralised for a month,add some Indian almond leaves and maybe some alder cones, and see where your parameters have got too! If the shrimp die then it may be worth going further but I wouldn't at this stage as it seems to be going so well. Again, wow what a tank, I am so jealous! Simon
    • Ricky ng
      I want to move to a caridina scape.. I've already have a quite mature 60p aquascape with mosses and anubias low tech but i use co2 only 1 bps or lower, dragon stone, inert substrate (la plata and jbl sansibar), water changes weekly and adding 1ml of Seachem Nitrogen and 1ml of Seachem Phospate, and adding a bit of ADA Mineral a day after, ADA Green brighty K every 2 day, previously i use tap water since i want to setup taiwan bee scape i already water change 50% of RO water.. Tds still 140-150, ph 7-7.5, kh 4, GH dont know i bought a broken one, i still try hard to lower down my ph but still can not.. so far i already tried to adding blue bolt, panda shrimp one each to test everyone is surviving so far.. what should i do next to stabilize the lower ph as well? And is there any fish recommended to keep with caridina? Harlequin rasbora?
    • jayc
      What plants are you going to keep in the tank? Low light mosses and slow growing anubias? then yes, that will be enough.   Good idea. Best to be safe.
×
×
  • Create New...