ph problems

[duked512]

first of all, you can blame sati for me being here .

I have a 25 gallon freshwater tank that i'm having a very difficult time getting the ph to what i think should be "normal". for several months now, the ph in the tank reads about 6.0 or so (yellow on the ph tester i use). its not green and yellow its just yellow. i figure this is pretty low so i should do something about getting it back up to 7. i've been doing 10% changes every 4 or so days with fresh water and that's not seeming to help. the water i'm using is from our tap, and its a ph of about 8 or 9 (for whatever reason northern ohio tap water has a very high ph). i of course put some dechlorinating stuff in the water and let it sit before i put it in the tank.

ok, here's what's in the tank:
2 bela sharks (one is over 6" long, the other is like 3" or 4")
4 cory cats
1 pleco
5 head and tail light tetras
3 neon tetras
3 flame tetras

i use only an undergravel filter, one spout has carbon filter in it and the other spout has ammonia filter. i change these every 2 weeks or so. light in the tank is on about 8 hours a day. i have no live plants in the tank (i've had horrible luck with plants so i got plastic ones).

i've tried using those "instant ph" packets and they dont seem to do much of anything but waste my money lol.

the fish themselves seem in great condition. they are very active and have no problems with fin rot or anything. hell even the pleco comes out when the light is on!

any help you guys can offer is appreciated.

 

[Madame_X]

Don't mess with PH adjusting chemicals. In most cases, the adjusted PH won't remain stable and your fish will be unhappy.

Its unusual that your tapwater has such a high PH but your tank has dropped down to 6. Usually a high PH equates to a high KH. You really need to test your carbonate hardness to find out why the PH is so low. Something must have caused the KH to drop.

I would increase your water changes to maybe 25% twice a week until it stabilizes. If you still don't have any luck, you can add a media bag full of crushed coral to your filter or add a piece of Texas holey rock to increase the KH.

For what its worth, while a PH of 6 is kinda low, there are plenty of fish who like soft water. What concerns me is that your tap water doesn't sound soft, which leads me to believe there is some issue in that tank dropping your PH/KH.

Good luck!

 

[duked512]

ok, i used our KH testing stuff and i heres what i came back with:

tank: <1deg dKH
tap: 5deg dKH

how would i add the coral or holey rock to my tank if i dont really have a filter to put it in? the entire bottom of my tank is technically the "filter".

 

[Madame_X]

Go with the holey rock, then. It makes a nice decoration and the smaller fish like to swim through the holes.

Something in your tank is definitely robbing the KH, though. A KH of 5 should be fairly stable. You definitely don't want it much lower than 5 or you will be subject to PH swings (like you're experiencing now). Do you vacuum the bottom of your tank when you do water changes?

I almost wonder if a build-up under the undergravel filter is causing a problem. You may want to think about switching to a power filter at some point in the future. I've never used one but I've heard nothing but bad things about the UG filters.

Since your fish don't seem stressed, try this. Before you throw anything in to bring up your KH, do a thorough vacuuming of the bottom of the tank and change about 25% of the water twice a week. Give it a couple of weeks and see if it starts to go back up.

 

[TankGirl]

How long has this tank been set up? There is definitely some acidifying processes going on to lower your pH this much, not to mention the KH.

Follow Madame_X's sage advice and keep us posted.

 

[duked512]

with each of those water changes i do a gravel cleaning. it *always* sucks up tons of crap. i'll keep cleaning out the rocks a few more times and see how it goes.

i do like power filters more than UG. combination of the 2 probably cant hurt.

 

[duked512]

tank has been setup for about 2 months now. it started out ok, but you see how things are now

 

[TankGirl]

Could you test the pH of your tap water after it has sat in a cup for a day? That might shed a little light on the issue.

A relatively new setup should not have accumulated acidifying gunk so as to drop the pH that dramatically, but you are essentially overstocked with those fish (esp. bala sharks and pleco) so there must be quite a bit of waste produced that I doubt can be handled efficiently by the UGF.

What are your readings for ammonia, nitrite and nitrate?

 

[duked512]

ok, here are all the tests

top row, left to right
1) PH 1 day old water that is treated with stress coat and ammo lock
2) PH fresh tap water
3) PH tank water

bottom row, left to right
1) ammonia test (it should be clear if there is no ammonia)
2) nitrite test. i lost the cards so i really cant tell you what it means. i'm using a aquarium pharamaceuticals (doc wellfish) testing kit, so if someone could match those up it would be appreciated

edit: nitrite test not nitrate

 

[duked512]

oh, i do not have a tester for nitrate.

 

[tsaraber]

Colors vary between the camera taking the pic and my monitor settings naturally but here's how it looks to me:
The PH of your tap water that's been sitting a day appears to be pretty close to 7.0 - There is a LOT of ammonia in your tank so definately keep up your water changes. There doesn't appear to be any nitrites though but considering how high your ammonia is you're most likely going to end up with nitrites pretty soon.

Do you by chance have driftwood in your tank? Because that will definately lower your PH. And make for sure there are no dead fish stuck somewhere because I think that will cause a lower PH as well.

 

[Madame_X]

Do you by chance have driftwood in your tank? Because that will definately lower your PH. And make for sure there are no dead fish stuck somewhere because I think that will cause a lower PH as well.

Driftwood alone wouldn't drop the PH from 7 or 8 down to 1 with a KH of 5. Something else is causing that PH to drop. A dead fish is a possibility, especially considering the amount of ammonia in the tank (I agree that it looks like a considerable amount).

There is either too much waste for the UG filter to handle or you're not getting enough gunk out when you vacuum. With that level of ammonia, your fish are in danger if it isn't reduced pretty quickly.

Keep going on those water changes and THOROUGH vacuumings.

 

[Voodoo Chilli]

I think Madame is exactly right: the pH drop sounds like it could be caused by a heavy load of dissolved organics in the water. I bet the UGF is the main culprit but there could also be unseen dead fish, decaying food, etc.

 

[duked512]

no driftwood, and dont think its dead fish. we take a head count almost every day and everyone is accounted for.

its probably just lots of waste in the gravel. every time i clean the gravel there is just tons of stuff. i changed the water yesterday so i'll wait a few days and change it again. i'm going to see about getting a power filter for the tank, and get off my lazy ass and setup our bigger tank to reduce the number of fish in there.

thanks guys