pH problem

[Everlasting]

I have a 29 gallon tank that's filter with a Marineland Penguin Bio-Wheel 200b system. I've got the temperature set to 75 degrees, I use tahitian moon sand as substrate and have silk plants and driftwood in the tank. I keep community fish in it.

My tap water is always very alkaline and this has never seemed to both the community fish in the tank, or my betta's in their 3 separate tanks. I generally do not bother checking my pH levels every week because I've never once in 3 years had it show anything other than bright blue. My red female swordtail died yesterday, so I immediatly because checking my levels and nitrite, nitrate and ammonia were all fine. When I saw all those were fine I checked the pH and it was very acidic. I did a partial water change and checked the pH of the tap water which was again very alkaline. The water change brought the pH to about mid level on the scale.

My question is, what is causing the pH to suddenly become acidic? Am I perhaps overfeeding them? Would that affect it? Or anything to do with the substrate ? I stir it weekly and it's (unfortunatly) FULL of malaysian trumpet snails...

Any help would be greatly appreciated!

[missileman]

I have heard that driftwood will change your PH but I don't know by how much or what direction.
What was your PH readings? and how much change from your tap?

[Everlasting]

My pH dropped to 6.0 and my tapwater is 7.6 consistently. The tank has been fine for 6 months almost now without ever having an issue with the pH.

[fort384]

How long has the driftwood been in the tank? This would be my guess as to the culprit as well. That is a pretty large pH swing though.

[jsoong]

How often do you do water changes?

Decomposing fish waste creates acids. <NH3 to NO3 gives off H+, that is acid.> If you have not change water for a long time, you could exhaust your buffers & cause a pH crash.

Driftwood may do the same (as it rots slowly, it releases acids). Generally, you don't see a huge pH drop like yours in well buffered (alkaline) water unless there is a ton of organics on the wood <like dead algae, really rotted bark, leaves, etc.>.

[Everlasting]

I do water changes weekly, and stir up my substrate at the same time. The wood has been in the tank since I set the tank up so about 6 months. The driftwood was a very old piece. It was purchased 15 years ago but only used back then for about a year as it didn't work with the underground filtration system my dad had in his tank.

I'm currently being overrun by malaysian trumpet snails which im trying to get rid of, that wouldn't have anything to do with it either would it?

[jsoong]

Snails remove carbonates from the water to build the shell, so I suppose it is theoretically possible to drop the pH that way. Although with regular pwc, it is pretty unlikely.

[JWALK2828]

is it a good idea to stir the substrate? i find madd fecil matter goes in the water and i was concerned - is this alright?

[Floyd R Turbo]

I have come across a similar situation. I have a 55 that I set up on 1/1/9 and made some discoveries. Our tap water is consistently off the scale - over 8.8, which is as high as API test goes - but my tank water stabilized around 7.2 then seemed to slowly drop to 6.8 or so. I also have a large piece of driftwood, but it's a new one. I use a UGF with power heads and have a medium-stocked community tank with plenty of plants. I had a cover on the tank to keep the swordtails from jumping, which I found out might have been trapping the O2 out of the tank, which can cause a pH drop.

I replaced the back plastic with egg crate to allow fresh air in and pointed one of the PH jets toward the surface to give it some chop, did a lot of gravel vacuuming, upgraded my light fixture to a medium level from a low level, and cut back on feedings and my pH slowly rose back to around 7.4-7.6 and it seems to stay there now.

I do a 2-3 gallon pull out of the 55 into my 10g fry tank (because I don't want them to get a huge pH swing) and replace it with the tap water, but I really don't think that has a lot to do with it. Before I had the 10g set up, I did a 25% change one day and a day later my pH had not changed significantly. I did a 30% change on 3/1 and my pH went from 7.2 (on 2/27) to 7.6 (on 3/2) and then have done 2-4 gallon changes daily since then and it stays around 7.5.

Don't know if this helps, but it's just my experience

[Everlasting]

Originally Posted by JWALK2828

is it a good idea to stir the substrate? i find madd fecil matter goes in the water and i was concerned - is this alright?

When I set up the tank I was told that if you do not stir up the sand on a weekly basis you run the risk of getting hydrogen pockets which can kill your fish. So I always stir it up after I vaccum it. My Tahitian Moon Sand doesn't allow fecal matter to get under it, it all lays on the top so I just vaccum it first and then stir it and there's no problems with anything floating around in the water.

[Floyd R Turbo]

Oh, also, overfeeding will cause a pH drop, so it's a good idea to cut back on your feedings, say one light feeding a day for a week and see if that helps.

And on the Malaysian trumpet snails, they are actually very good for the gravel, they stir it up naturally so you won't get those pockets of bad stuff. So even though you may not like them, they're actually very beneficial to have. They also eat all the food your fish don't, which counteracts overfeeding. Good judges of when you need a water change also, they'll crawl up the sides of the tank during the day in that case. Plus you'll never get rid of them. Check this out How to Succeed with Malaysian trumpet snails, Melanoides tuberculata, with pictures

[JWALK2828]

my substrate is gravel and rocks. not sand..

[JWALK2828]

hmm, thats cool. I dont have Tahitian Moon Sand

[Everlasting]

Originally Posted by Floyd R Turbo

Oh, also, overfeeding will cause a pH drop, so it's a good idea to cut back on your feedings, say one light feeding a day for a week and see if that helps.

And on the Malaysian trumpet snails, they are actually very good for the gravel, they stir it up naturally so you won't get those pockets of bad stuff. So even though you may not like them, they're actually very beneficial to have. They also eat all the food your fish don't, which counteracts overfeeding. Good judges of when you need a water change also, they'll crawl up the sides of the tank during the day in that case. Plus you'll never get rid of them. Check this out How to Succeed with Malaysian trumpet snails, Melanoides tuberculata, with pictures

I dont mind having some in there but the 300 or so which are currently overrunning my tank is just a bit much. I've purchased a loach to try and keep the population better in control.

I've beginning to wonder if the driftwood is part of the pH problem? It was about 25 years old given to me by my father and while it was purchased for a tank from a lfs, it sat out in the air for probably 20 years. I'm wondering if something got into the wood that is now leeching into the water...