I don’t understand the science behind it nearly as well as you do, but going back to my first tank’s spreadsheet: - my tapwater is pH 7 but soft. pH remained 7 for the first 14 days - somewhere in the first 2 weeks I added 2 small pieces of new mopane - pH started dropping by day 15. By day 17 it was 5,5. - by day 20 it was 4,5. Lfs confirmed reading. Removed driftwood, added crushed coral - mini nitrite spike by day 22 or 23 - boiled, soaked, pressure cooked wood. Still dropped a jug of pH 7 water to 5,5 in 24h
That is still a naturally occuring pH and there is a source of H+ ions. I wouldnt call that a crash though. Did you lose any fish when this occurred?
Just to further elaborate - in the amazon there are sections that can drop to pH 4.5. This water is soft, unbufferred and has a source of tannins that causes the pH to drop to this value and yet it will never suffer a pH crash. The only difference here is that it is an infinite amount of water vs our few 100 L aquariums. So it is essentially and continuous WC and yet the water pH remains stable at pH 4.5. I am not saying I am right, I am simply saying that I am skeptical regarding pH crashes. I have kept fish for about 20 years and have never experienced one. The science behind it doesnt add up to me - there has to be a source of H+ ions that can drop the pH rapidly in order for this to occur. And as you move away from nuetral to acidic the source needs to increase 10x for each 1 pH drop.
Thank you Ferdie I'm trying to raise the ph because many people I've spoken to have said that it's too low I must sort it out. And it's just pfs, nothing else.
When last was that pH pen of your brother been calibrated. You really must calibrate it correctly to get the correct reading.
It IS real. It has happened to me once and I lost so many fish - all with burn't gills - was not a pretty sight! I thought my water was at 6.5 and when I measure it is was 3,5 ... 2 days later
Wish I knew - must have been something the water - I started adding more borehole water to buffer it and it never happened again.
All of this made me reach for the pH test kit this morning and I got a couple of surprises... nothing too hectic but still. Tapwater tested 7 as expected. Two biggest surprises: - 38L down to 5,5 with the (old and leached) mopane added in the last month. Realised I’ve forgotten to add crushed coral here. Will correct. - River tank (1,5m) tested 7,5 which is higher than expected and desired for the soft water fish. Tested twice. I have crushed coral in the filter but @TheGrissom am I correct in understanding that it shouldn’t push pH up beyond 7? Must be the sheer amount of river stones? Strangely enough my ramshorns in the tank are pitted so I really didn’t expect high calcium in the tank.
I had a look at some solubility charts of calcium carbonate. About pH 8 its stops dissolving completely but by pH 7.4 the solubility is so low it can be seen as negligible. So the pH should end up somewhere between 7 and 7.5 in reality
Hey, sorry to bring up this old conversation again but I thought it would be best to add onto this very informative thread. My situation is quite similar and my method to rectify the same issue I am facing would be the same, using some sort of buffer. As @A new day would very well know the water here is very unstable and has rumoured to cause hair loss and not safe for consumption indefinitely. Getting to my issue: so my tap water was stable at pH 7 when I started till about 3 weeks ago. People in my building complained the water was different and some even complained that it was a little smell of chlorine when using for washing up. Of course I immediately tested my tanks and the tap water which got me completely shocked. My tap water has dropped to 6.4 and with water changes over the last 3 weeks my fry tank is at 6.8 (this is newly set up but seeded filters were used) and my main tank sitting at 6.4. amazingly the water has zero chlorine but I still use seachem safe just incase The options I have are using seachem Malawi buffer and cichlid lake salt or sodium bicarbonate which I have on hand. My fish are still doing okay and I've had a pair spawn today even but it's not ideally where I'd want it. I was okay with a pH of 7 but if I'm going to be buffering I want to have it closer to 8. Any thoughts?
Hi @Shabir, and best of the new year to you. Firstly, what type of fish do you have? Some species are very adaptable and can thrive at a pH of 6.4. Fish's metabolism naturally causes pH to drop over time if no buffering elements are added to the water. All the buffer salts you have and sodium bicarbonate will work, but it might not be necessary and could become expensive. I do add a little bit of salt with my water changes to add some salinity for general health. I also add very little sodium bicarbonate to my synodontis tank. However, whatever you do make sure you do it gradually/. The best thing I would recommend is getting crushed coral from your LFS and just keep some of it either in your substrate or your biofilter. This is the best way to make sure your pH stays above 7 in a gradual and natural way. You might not get to 8, but as you said, your fish are breeding so there is no real concern here I would think. The biggest danger with low pH is that at low oxygenation, heavy feeding, high stocking densities or CO2 injection etc, you can potentially have a pH crash where the pH quickly falls below 6 which could be harmful to your fish. Adding crushed coral will prevent this. The key here is consistency rather than targeting a perfect set point. Just some of my feedback
Hey @Zuraki happy new year to you. I trust you are safe and healthy during these struggling times. The fish I have are lake Malawi cichlids. The only fish which are breeding are the s.fryeri which are haps. My peacock's and Mbuna are refusing to breed. I had yellow labs breed once 6days apart from the s. Fryeri so I'm going to know in 5 days if they are at it again or not. Bicarb I have, the cichlid salts are costing me just under R800 so not purchased yet so if I can get away by using bicarb only I would not make the purchase, however I would buy them here if I really have to. If not I would just wait till I come to SA hopefully in June and bring those with me back at more than half the price. When I kept before I was able to keep the pH at 7.5 with crushed coral but this was in SA and I cannot get it here. Argonite is very expensive here also and to do my whole tank of 1.5m will land me a few thousand which I really wouldn't want to spend on right now. I also add in a little bit of rock salt every now and then, when I notice a fish who's fins look a little nipped. And once a week I soak food in Epsom salt and skip a feeding just to help with digestive system
Funny enough, i was doing some reading up on 'PH crashes' a day or two ago, to help a friend and today i see the subject coming up again Fortunately I have never had a problem with PH dropping in any of our tanks We are on borehole water which is fairly hard, my PH out the tap is around 7.5 and remains stable at that between waterchanges despite the heavy bioload, PFS and some driftwood We feed heavy daily, where we have pregnant girls, we feed twice a day We do run an insane amount of filtration and media Our friend is on Municipal water, also has big tanks Pfs, small amount of driftwood Tank is probably slightly more overstocked than ours and less filter media He only feeds every second or third day which reduces bioload slightly His PH out the tap is 7 and 3 days later its at 5.5 Why.... On one or two articles I read it said that too much build up of carbon dioxide in the water causes the PH to gradually drop They recommended increases aeration and water movement to assist in gas exchange at the surface and releasing the carbon dioxide and increasing oxygenation in the water which would help in not allowing the PH to gradually drop At @Zuraki ... @TheGrissom ... anyone else's thoughts on this? Is this true? Truth be told... my tank's surface water looks like the ocean I run 4 big air stones, 3 wave makers and my sump runs 18000l /ph so agitation of water is crazy
The buffering capacity of the water is being used up which is why the pH is dropping. CO2 will reduce the pH as it dissolves in the water forming carbonic acid. What is the kH of the tank. If the kH is quite high the pH should not change as the kH measures the buffering capacity of a tank which is the ability of the water to resist pH change essentially
I remember bookmarking this a while back - Marco gave an overview on things: https://www.tropicalaquarium.co.za/threads/ro-water-and-its-basics.6904/
