Why Is My pH So Unstable and What Can I Do About It?
The tap water that I put in my fishtank is alkaline (tap water is about 7.2 – 7.4). I always test my water just before doing a water change each week. By the end of the week when it’s time to do a water change, my tank water is acidic, like 6.2 or even lower. So within a week (or less) it’s gone from alkaline to acidic, then back to alkaline again when I do a water change. No doubt this is harming my fish as I’ve had a few casualities that I couldn’t explain any other way.
Why is my pH doing this? And what can I do about it?
My tank specs:
45 gallon, 26 degrees celcius, freshwater community
Ammonia and nitrite consistantly show zero.
According to aqadvisor.com, my stocking level is 61%.
Tank has a medium-large piece of driftwood (I know this can affect the pH, but so drastically?), river pebbles, plastic plants.
Two canister filters so it is well filtered. Weekly water change of about 25-30%, gravel is syphoned during this.
Thanks for your help! :)
I put the driftwood piece in there when I first started the tank, about 3 or 4 months ago. The yellow coloured water it created has long since disappeared. Could this still affect things?
I haven’t been testing my tap water properly apparently, I will try again, thank you. :)
I just got a thought… would putting a bit of shell grit in the tank or canister help stablise it at all?
Tagged with: 4 months • ammonia • canister filters • casualities • coloured water • driftwood • fish • fishtank • gravel • grit • no doubt • plastic plants • river pebbles • shell • stocking • tank specs • tank water • tap water • thanks for your help • water change
Filed under: Alkaline Water Filters
Like this post? Subscribe to my RSS feed and get loads more!
My best bet is that it’s your driftwood causing this especially if it’s a large piece. Tannic acid in the wood leaches out. Since having a pH bouncing around can cause harm to your fish so I recommend you remove the driftwood and soak it with hot water over quite a few days, if not weeks. If the piece is small enough to boil, then the better.
What ever size it is, you will need to leach out those tannins in a bucket, tub, pot of hot de-chlorinated and conditioned water and let it sit. After 12 hours (obviously not when boiling or using a stove), you change out the water and re-fill. If you see a yellow tinge at any point, you know that the leaching is working and the lighter the water gets, the sooner you will be able to place the wood back into the tank.
Good luck!
EDIT: I would try using crushed coral or sea shells, but do it at little increments over a week or 2 so it the GH slowly rises and hopefully the pH will as well.
If after that if you are still having issues, I would go with taking out the driftwood and soaking it more. Good luck.
The driftwood is certainly contributing to it, and there could be a lack of hardness in your water source as well, which allows for faster pH drops.
You may also be testing your tap water incorrectly. A lot of people test it straight out of the tap, but you should let it sit for an hour and then test it, to get a correct reading. The true pH can be quite different compared to the false one.
the only thing i could think of is the driftwood, if you have recently added it then it will make the water acidic and drop the PH. but soon it will not affect the PH that much. if you are using co2, this will also have the same effect. my water is hard and the PH is 7.2 and when i use co2 it drops to 6.5-6.8PH
peat moss, co2,driftwood reduce PH and make the water acidic.
while rocks, lime stone etc make the PH higher.
if you dont want the ph to drop or the water to get acidic then remove the driftwood. but i don’t think it should effect your fish anyway, fish like the driftwood, if you have tetra type fish then this is good for them.