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Thread: Ph stability

  1. #1
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    Don Speers

    Default Ph stability

    Over and over again the need for pH stability is stressed (with good reason) to maintain happy and healthy discus. The question came up in a discussion and I realized that although I have a personal opinion (variance of >0.2 with water changes is too much) I had never actually validated that opinion. A google search and forum search did not net me any additional feedback other than one author that recommended <0.5. That is too much variance to my mind. So, your perspective on what constitutes stable pH? Thanks

  2. #2
    Moderator Team LizStreithorst's Avatar
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    Default Re: Ph stability

    I found from experience that .4 was too much but that's all I know. Since I found that out back when I was new, I've aged since.
    Mama Bear

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    Default Re: Ph stability

    How often are you checking ph, Don? I have often read here that ph is critical for discus. Mostly being vigilant for a "crash". One day I am going to get hit with it but for me in the past 2 years with daily water change I have yet to check the ph. So far lucky is suspect. As such this will be a good thread for me to learn that which I do not know.

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    Silver Member Willie's Avatar
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    Default Re: Ph stability

    I think the reason you can't get a straight answer is that the question is more complex than simply a pH change. If the water is soft and therefore has low buffering capacity, then pH can drop precipitously with a small increase in hydrogen ions. I've measured pH in R/O water and pH values drift constantly. Hard water has very high buffering capacity, so changing the pH represented a drastic change in hydrogen ions. A pH drop from 5 to 4 has less effect than a pH rise from 8 to 9.

    Don: I know this is completely unhelpful, but at least it's an explanation.
    At my age, everything is irritating.

  5. #5
    Moderator Team LizStreithorst's Avatar
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    Default Re: Ph stability

    Everybody's water is different. My own water is weird. Comes from the tap at 79 TDS and my Discus won't produce wigglers unless I use almost all RO. At least I'm lucky enough to be able to use all my RO waste on adults and grow outs. I wish I understood more about my water. I also wish that we had a water guru among us. I know that they exist.
    Mama Bear

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    Default Re: Ph stability

    Quote Originally Posted by Willie View Post
    I think the reason you can't get a straight answer is that the question is more complex than simply a pH change. If the water is soft and therefore has low buffering capacity, then pH can drop precipitously with a small increase in hydrogen ions. I've measured pH in R/O water and pH values drift constantly. Hard water has very high buffering capacity, so changing the pH represented a drastic change in hydrogen ions. A pH drop from 5 to 4 has less effect than a pH rise from 8 to 9.

    Don: I know this is completely unhelpful, but at least it's an explanation.
    I don't know, Willie, every little bit of knowledge learned is knowledge gained until one day the proverbial light bulb flicks on in the head and then you get it. I just now tested pH in two tanks. One had 15% tap water change 12 hours ago read 7.2. The other has peat in the filter which would suggest a lower pH but instead it read 7.6. My tap water is 7.8.

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    Default Re: Ph stability

    Quote Originally Posted by LizStreithorst View Post
    Everybody's water is different. My own water is weird. Comes from the tap at 79 TDS and my Discus won't produce wigglers unless I use almost all RO. At least I'm lucky enough to be able to use all my RO waste on adults and grow outs. I wish I understood more about my water. I also wish that we had a water guru among us. I know that they exist.
    Seems to me that would be Willie. RO, Liz, what is it, what does it cost, and how would I know if I wanted to use it? I don't want something that I don't need.

  8. #8
    Moderator Team LizStreithorst's Avatar
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    Default Re: Ph stability

    peewee, I do what I have to do to allow my Discus and Rams to have their eggs hatch out. Kenny has a pH of 7.8 and he is able to produce fry in it. Mine is pH 6.8 from the tap and 7.2 aged and I need RO to breed. If I didn't want to breed I'd just age. You do what you have to do to get what you want. That's when the passion overtakes good reason.
    Mama Bear

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    Default Re: Ph stability

    A 0.2 pH swing won't cause any harm at all, people with heavily planted tanks will usually see more of a pH swing than that between night and day. I personally would say anything up to 0.5 would be fine too. One of the advantages of frequent water changes is stability, not just pH but other things too, this is why drip feed systems work so well, they give you a rock steady parameters.

    While it's true that a 90% water change once a week is more effective at removing waste such as nitrates, smaller, more frequent changes will maintain more stable parameters in general.

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    Silver Member Willie's Avatar
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    Default Re: Ph stability

    Remember that it's KH which effects egg development, not pH. Specifically, it's calcium ions that causes membranes to block sperm penetration. KH is primarily composed of calcium and magnesium. So pH and egg development are not directly related.

    Willie
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    Default Re: Ph stability

    Some really good info here. Agree whole heartedly with your posts Willie.


    What Liz said about everyone's water is 100% the absolute truth. To anybody reading this thread in the future, please pay attention to exactly this.

    What works for some people here, or even most people here might not necessarily work for your water.

    Large water changes are talked about in this community as the ideal method of successful discus health/growout, but the term large is secretly very vague and dependent on your water conditions.

    My own water has extremely low KH(1-2), and even with some crushed coral, unless the flow is correct and I'm truly running my water properly, my PH will end up dropping significantly. I've had it drop from 7.2-6.0 or less within 24 hours. And no this isn't CO2 aerating off gassing. This is from multiple days' worth of aged water after a 90% water change without adding any buffering capacity. I specifically remember doing a fishless cycle with pure ammonia and having multiple PH crashes during the process. At the time I couldn't figure out exactly why, but now it makes more sense to me that a low buffering capacity means less of a nitrogen cycle as converting ammonia to nitrates uses carbonate hardness. To fix my issues (crossing fingers), I am using 2 tsp baking soda per 60 gallons to get my KH to 4-5.

    Anyways, another thing I'd like to bring up is a PH change can be more hurtful depending on which direction it goes. A PH RISE can be more damaging than a PH DROP. People with more expertise can explain this better than I.
    Amateur discuskeeper, Professional doofus

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    abe petek

    Default Re: Ph stability HELP

    Hi everyone!I am very new in the forum.I bought rodi for reduce ph but nothing any change still ph 10.How can i reduce ph?I am very disappointed HELP please
    ?

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    Registered Member Shan_Evolved's Avatar
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    Default Re: Ph stability HELP

    Quote Originally Posted by senjori55 View Post
    Hi everyone!I am very new in the forum.I bought rodi for reduce ph but nothing any change still ph 10.How can i reduce ph?I am very disappointed HELP please
    ?
    Welcome to our forum Abe!

    I would advise you to make your own waterworks post and include as many details as you can, ex: location of your water supply, aged or not, RO/DI system details, and water parameters to start
    Amateur discuskeeper, Professional doofus

  14. #14
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    Default Re: Ph stability

    Abe if your RODI system is working then your value is false, which can happen with home test kits because there is so little buffering left in filtered water. You can confirm this by checking both the kH and/or gH/TDS, both of which should be near 0. Pure water is actually acidic due to dissolved CO2. Depending on ambient temperature and CO2 partial pressure actual pH can be as low as 5.5. One way to test this is to dilute vinegar with distilled water to a ph of 4, mix 1:1 with your rodi sample and see, if it really is 10 the resultant mix will be pH 7.

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