Falling PH

[O]

Hi All,

I need your help! Over the last 2 weeks I've had a problem with my PH falling after WC. Can't explain it. I have not changed my set up in any way. The fish are fine, however I'm concerned with the difference of my WC PH and tank PH. The tank is a 55 gallon with 8 adult discus and some cories. Running AC 300(with two sponges) and Two air driven songe filters.

Daily WC of 40% to 50%
WC PH 6.5, within hours falls to 4.0 to 4.2.
Ammonia at zero
Nitrite at zero.

Now this only started about a week and a half ago. I've never had it settle below 5.8PH before. Any ideas why it falls to 4.0PH ?

Thanks
O.

[yogi]

Has the kh or gh of your tapwater changed at all? Sometimes it fluctuates with the time of the year. When was the last time you squeezed out your sponge filters? If it's been real long the accumulation of waste can cause ph drops. Try squeezing them out in a bucket of water water from the tank. This goes for sponges in the tank as well as the sponges in your aqua clear fiters.

I also want to add that 8 adult discus is pushing the limit of the 55. There waste can also be causing the ph drop.

[O]

Hi Jerry,

I squeeze my sponges every two weeks or so. So it can't be that. I'm thinking the tap water might have changed. I'll check tonight.

Thanks for your help.

O.

[daninthesand]

When you say you squeeze your sponges, how aggressively do you squeeze them? I noticed the ph in my tanks, got a bit lower, not as bad as yours mind you, when I started cleaning my sponges more regularly. I was probably being TOO thorough and sqeezing the sponges too hard and reducing the biofiltration. All I know is I started being more gentle with the sponges and the problem stopped.

Just a thought.

Daniel

[O]

Daniel,

That's interesting. Perhaps I'm being to thorough while cleaning. But I've always done that and had no problems before. Also, if the bio-filter is affected, than the ammonia level should be raising and I'm not detecting any. That was my first thought actually - higher ammonia levels would make the water more acidic and therefore lower the PH, but it does not appear to be the case here. ??? ???

O.

[daninthesand]

Yes, you have a point about rising ammonia. In my case I was just measuring ph because i had recently bought a ph meter. (thanks RandalB!) At the time I never bothered to measure ammonia, because it was only after i stopped really aggressively cleaning my sponges did i think about the affect on the biolfilteration. My conclusions regarding this came about in retrospect.

I could not explain it any other way. Incidentaly the ph meter also has a conductivity meter built in and there was no appreciable difference in the conductivity of the water i was making ph measurements of. So there had not been a change in the buffering capacity of the water during the time I had increasing ph numbers. As yogi suggested you might want to see if this is the case. If the hardness of your water for some reason is now lower(and hence the buffering capacity is lower too), it might explain the lowering ph.

Another possibilty is the discus in that tank have grown to the point of outgrowing the capacity of your sponge(s). Maybe add another cycled sponge into that tank and see what happens?

Daniel

[O]

What can I use to increase the buffering of the water?

Baking Soda? How much?

I still have some Seachem Cichlid Salt leftover from my African days.
Can I use that?

Thanks
O.

[daninthesand]

O.

I don't suggest you start "messing" with your water.

You need to find out what has caused this sudden ph change. Heck I wish I could have my water register ph in the mid to high 5's! But not due external factors which might otherwise be degrading the quality/cleanliness of the water.

You said this is a new phenomenon in your tanks. Something must be causing this. Are you measuring the ph of the water in your TANK at 6.5 immediately after the water change and the tank changes to the 4's in a matter of hours? OR are you saying the water you are adding to the tank is ph 6.5? If so what is the ph of the tank before the water change?

Do you have other tanks where this is happening also or is this the only tank you have?

Start asking yourself these questions. Ones that will lead to what has changed in your situation. I know you said you have not changed your water change routine, but if you ask yourself these questions you might find your answer. But adding stuff to your tank to correct what was an OK situation before, is not the answer in my opinion.

Let us know in as much detail as you can about your situation, and maybe we can help you figure this thing out.

Daniel

If you have BB what I assume, check if there is any trapped crap somewhere. i.e. Overflow chamber and so on.

If you have eliminated that check you tap KH, gH and TDS/Conductance.

I assume with 8 adults in a 55 there could be a chance of a too high Bioload depending on you feed schedule and amount.

Sodium Bicarbonate has a short live span for the lack of better words. The span is about 24 hrs. So if you use prepared water that ages for 24 hrs, that becomes mute unless you add it at the very last moment without knowing how it will turn out.

A better solution would be to use crushed coral placed in a pantyhose in the A/C. Crushed Coral depletes over a longer time period

Ronald

[April]

i agree with all of a sudden theyve outgrown their environment and the filters bio capabilities. as it happened to me. my fry were doing great but growing like wildfire. all of a sudden...low ph and they got freaky. lost 2. so i moved them to the 100 gallon and voila back to great fish growing fast and healthy and no more sliding ph. i added way more filtration. id add another filter.
i made a huge filter out of a rubbermaid.. i have a powerhead pumping up to the rubbermaid and a spray bar inside it and a spigget for the water to pour back into the tank from above the tank. with large sponges. filled. you can add coral or oyster shells or bioballs or what have you. but now i have mega filtration and..no massive current. i also have an aquaclear. now.the fish are big and healthy.
i lost a few batches from falling ph as their biolaod got too demanding and ph shifts. learnt the hard way. I also got the ph meter from Randal and it didnt fix the problem but it sure helped me to see what i was doing wrong.
i also squeezed more when i was worried i wasnt squeezing enough. so could be a bit of both things going on.
Let us know how it goes.
you can also try ph proper for a bit till it gets stabilized. but its costly. but it got my fish tank stable and the fish from going through the changes. baking soda works.but not for long.
but..for sure sounds like its time to move some to another tank. or a bigger tank.

Dang,

"oyster shells"
That was the other I was looking for lol, but could not remember it.
Maybe I am getting old.

Ronald

[O]

Thanks Everyone!

I'd agree that the bio-load is too heavy, if I was reading elevated ammonia levels? I'm not registering any ammonia or nitrites at all. What am I missing? To my knowledge and experience higher levels of ammonia and perhaps dissolved organics can make the water more acidic and therefore lower PH. However, just to be on the safe side I’ve added two more sponge filters.

Here're some new readings:

Problem Tank(55g BB)

PH 4.0 (interestingly enough it has not moved any lower after settling at 4.0 last night)

KH - 6 dKH
GH - 10 dKH
Temp 86F
Ammonia - 0
Nitrite – 0
The fish are fed twice a day.
WC - 50% daily

Tap Water:

PH - 6.8 (From the tap filtered through two 10" Carbon blocks)
KH - 6 dKH
GH - 10 to 12 dGH
Temp 86 F

Aged Overnight:

PH 6.5
KH - 6dKH
GH - 10 dGH

Another tank(46 Gallon Bow Front running Eheim 2213. Housing 12 2" to 2.5" juvenile discus & 4 cories. this is a temporary set up, I'm cycling another 55 gallon that was affected by the black out.)

Measured before the WC.

PH - 6.4
KH - 6 dKH
GH - 10 dGH
Temp - 86 F
Ammonia - 0
Nitrite – 0
WC - 70% daily

I think, the suggestion that my sponge filters might the problem, may be correct. I’ve made a gradual water change of 20%, and squeezed all the sponges. PH went up from 4.0 to 4.4 and has not moved down in the last tree hours. Yesterday, I watched it drop about half a point every half an hour.

The fish however are a not showing any signs of stress. No stress bars, no skittishness, and all are eating as usual.

If there are no changes in the PH levels over the next 24 hours, I will try to raise it back to normal levels over the next few days just through WC's without adding anything else to the water.


Thanks Again for your feedback.

Oleg