Rocks an pH Question

Discussion in 'pH' started by MindTravel3r, Apr 10, 2010.

  1. MindTravel3rValued MemberMember

    Rocks and pH

    Hi Folks,

    Both my aquarium and my tap water measure a pH 7.8, and my aquarium has stayed stable at 7.8 since I set it up in early February. I know that this is a little high for community freshwater fish, but I acclimate my fish very slowly, and I have been operating under the assumption that stability of pH is more important than the actual number.

    I was recently on vacation in North Carolina, where I picked up a number of rocks while out on hikes (I am attaching a few photos). I read an article that recommended putting the rocks in a bucket of aquarium water for a week and compare pH before and after the rocks sit for a week in the bucket. So upon returning last week, I did a water change and filled three buckets with aquarium water in which I placed two or three large rocks in each bucket so that the water just covered the rocks. After sitting a week, the pH dropped from 7.8 to 7.2 in two of the buckets and from 7.8 to 7.5 in the third bucket.

    What I did not do was test each day; therefore, I do not have any sense of how rapidly the change occurred. I plan to do another water change today, and change out the water in these test buckets and test at the one hour, three hour, 12 hour and 24 hour points to try and get a sense of how rapidly the change occurred.

    Ideally I would like to have the pH around 7.2 or 7.4, but I would prefer to not to have to manage pH on a weekly basis if I can avoid it.

    Do you think that adding these rocks would buffer the pH at a lower level, providing stability at a lower level? Or do you think adding the rocks could create a less stable environment regarding pH?

    Is it possible that there would be a short term effect on the pH, but over the long term the water stabilize back at the higher 7.8 level?

    Do you have any thoughts on acclimating the fish to the lower pH?

    Attached Files:

    Last edited: Apr 10, 2010
  2. ShawnieFishlore LegendMember

    im no rock expert, but those do look allot of a rock I use to keep my ph higher in my african tank....but seeing how your tap is higher, and you acclimate properly, id stick with not worrying about lowering it...otherwise every time you doa water change with the higher tap water, you could have issues....I hope some rock members can help more!

  3. MindTravel3rValued MemberMember

    OK, so I did a water change and changed out the water in the buckets with the rocks. I tested at 1 hour and there was no change to the pH. However, when I tested at three and a half hours the pH had dropped from 7.8 to 7.4. I will test again in the morning at 12 hours.

    Edit -- The three and a half hour test was done with the High Range kit. Testing at the 12 hour point with both test kits has led me to conclude that this reading (at three and a half hours) was likely about 7.5.

    Last edited: Apr 11, 2010
  4. leeishomValued MemberMember

    next time, use plain white vinager to test rocks that have 'raise PH' properties.

  5. MindTravel3rValued MemberMember

    I have already tested with vinegar and got no fizz at all. Both the initial vinegar test and my tests of leaving the rocks in buckets of aquarium water pretty much rule out any raising of the pH. On the contrary, they seem to be lowering the pH toward neutral.

    After testing at the 12 hour mark, the pH seems to have stabilized, It appears to be at the point that is exactly between the high range and low range API test kits. It is reading 7.4 on the high range and 7.6 on the low range. So, I am calling it 7.5.

    I will test again at the 24 hour mark and then daily for the week.

    The nagging question that I have is that if I add the rocks, and the tank buffers in the 7.2 to 7.4 range. How do I manage water changes with 7.8 pH tap water?
  6. ShawnieFishlore LegendMember

    take a container of just your tap water, and leave it out over night for at least 12-24 hours and I bet you will have the same range as you are getting now....the rocks wont work that fast either way :) by you leaving the water to sit , its giving you the true ph of your tap ....I would boil the rocks and go ahead and add them if it were me :)
  7. MindTravel3rValued MemberMember

    That very question of, "what would a bucket of water without the rocks do?" occurred to me this morning. And I think I agree that they will be safe. As I was leaning in this direction already, I am going to take your advice and add the rocks (after boiling of course).

    I suppose I won't really know if I have an issue with pH in the live system until they are in there.

    Thanks for the input.
  8. ButterflyModeratorModerator Member

    Beat me Shawnie!!! i was going to suggest he test his tap water.
    Rocks affect the pH generally by dissolving over time so such a short time wouldn't show that big of a difference.
    I personally would clean them and use them. You can keep a watch on your pH a month or so out if you want to but if it does raise your pH it will be very gradually and the fish will acclimate to them.
    I have cichlid sand and Texas Holey Rock in my Multi tank and have had for several years but I do weekly water changes and substrate vacuums and the pH is the same as it is in the tanks without the sand or rock. My thought is that enough of the dissolved rock and sand is removed by water changes that the pH isn't affected.
  9. ShawnieFishlore LegendMember

    not to mention where the tank is freshly cycled, the ph will fluctuate a bit....I have an african tank with a ph of 7.8 but my tap is 7...I just do smaller more frequent water changes to keep it up well as 100lbs of crushed coral LOL
    goodluck and share pics of the tank when you can :)
  10. MindTravel3rValued MemberMember

    OK, so I have added the rocks. The pH has held the first hour, so I am confident that if it goes down, it will be slow enough for the fish to acclimate. The cory's were a little freaked-out by the redecoration process, but seem to have settled down and couple have even ventured out to the front.

    I have attached a couple of pictures. Overall, I think it has come together pretty good. Thanks again for the feedback, it helped alot.

    Attached Files:

  11. ButterflyModeratorModerator Member

    I like how that looks. The Java Fern is a nice touch.
  12. MindTravel3rValued MemberMember

    Shawnie, it looks like you may have been right about these rocks being the type for raising the pH. After all that testing, and watching the pH go down in the test buckets, the pH actually went up from 7.8 to 8.0. I suppose you live and you learn.

    So far the fish seem to be fine. If I can manage a stable pH at 8.0, should my tetras and corys be OK, or is that getting too high to be safe?
  13. flyin-loweWell Known MemberMember

    I have about 12 corries that have been in my tank for about a month and my pH is about 8.2. I am planning on going to RO soon so that will likely change, I think as long as it is stable they will adjust.

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