Tap/Aquarium PH problems

[Dan06]

Here's my issue....

30 gallon tank, 2 Bala's, 1 Pleco, 1 Turquoise Gourami, all waiting for a 55 gallon to finish cycling.

My Tap PH is 7.0. I'm not exactly sure when the problem arose, but after a water change about 2 months ago, I noticed the PH was about 6.0 the very next day after a water change. I used the typical fix of Baking Soda over a course of 3 days, I raised it back to 7.0, which my fish are accustomed to.

Still now, I can do a water change & my tap PH will be 7.0, my tanks PH will still be 7.0 a week after my last water change with a teaspoon of Baking Soda.

Just yesterday, I did a 20% water change and again, the next morning, the PH had dropped to about 6.6.

Ammonia is 0, Nitrites is 0, Nitrates are less than .10

If I add Baking Soda, and make the sin of skipping a weekly water change, the PH will steadily stay at 7.0, but once I do a water change, regardless of how minimal it is, even if I just top the tank off with some fresh dechlorinated water, the PH will gradually drop until I add just a touch of baking soda.

Is there something wrong with the chemistry of my tank, or is does it have to do with my tap water source??

 

[SCFatz]

I've read that driftwood and some sustrates can lower ph.

Its also more important that it remain stable at whatever number then it is to be exactly 7.Perhaps wait it out and see if it settles in one spot.

 

[Dan06]

It will continually drop. I keep it at 7 because that is where I want it, and that is where I always keep it, hence it IS stable. After having the tank for 4 months, there has only been about a week total where the PH has been below 7.0, if you add up all the time it has dropped below 7.0

I'm just looking for the reason why, if I don't treat the tap water that comes out from the tap reading 7.0 after less than 24 hours in the tank, my PH will continually drop until I add baking soda, then it will remain stable until I top off the tank or do a water change... which is done weekly.


Also, your idea of 'waiting it out' is bad. Everytime I do a water change, the fish will be exposed to a possible episode of PH shock, for example - let's say the PH 'settles' (like you said) at 6.0, now I go to do a water change and in a 5 minute span, the PH in the tank spikes to 7.0.... You can't expect my fish to have a good experience during this time. Sorry, but I can't leave it alone and see where it settles. I hope you don't give this sort of PH advice to anyone else.

*note*

All of these fish are waiting for a 55 gallon to cycle, so don't worry about the tank being too small.

 

[trotty]

what fish do you have?

 

[SCFatz]

per·haps ( P ) Pronunciation Key (pr-hps)
adv.
Maybe; possibly.

I hope you don't give this sort of PH advice to anyone else

Just a suggestion based on my experience with my own tank.For whatever reason mine dipped for the first time after being up 6 weeks..first time ever.I did some checking and decided to wait it out and it dipped a little futher..to around 6.4 or so I guess...then it just hung out for a while before rising back to 6.8 and stablizing.Still have no idea why it dipped or rose,but its fine now.

Everytime I do a water change, the fish will be exposed to a possible episode of PH shock, for example - let's say the PH 'settles' (like you said) at 6.0, now I go to do a water change and in a 5 minute span, the PH in the tank spikes to 7.0.... You can't expect my fish to have a good experience during this time.

The amount of ph change will be porportional to the size of the water change imo.If the tap is 7 and the tank is 6 then a 100% water change will be required to get the tank to 7 ect..

There some other variables like water hardness that effect buffering of the ph,but someone with more experience will have to help you there...I'm sure someone can.

All the best sorting it out,

 

[Macrosill]

1st to truly check your tap ph you need to let it sit out for 24 hours to let the gas levels to equalize. What are you testing the ph with? Liquid regent or test strips?

Ph swings are dangerous, no doubt about it. You say you "keep" your ph at 7.0, exactly. This can be bad for your fish if you are constantly adding chemicals to keep it there. If the ph falls or rises even by .1 or .2 in less than 24 hours you are harming your fish. If the PH is 6.6 like you said above then you add a little baking soda to bring it up to 7.0 that is a significant ph swing.

Get back to us with the substarate and decos in the tank as well as your filter media and the type of kit you use and we can help you further.

 

[BillD]

Does anyone have some conclusive evidence that small fluctuations in pH have a detrimental effect on fish? I keep hearing about pH shock, but the ony evidence I have seen, points to the contrary. A planted tank will have daily fluctuations of pH when the lights are on or off. Since the TDS (Total Dissolved Solids) of the water doesn't change it does no harm. Incidentally, adding water of a pH of 7 to water of pH 6 will not cause a spike to pH7. The only possible problem I see, is that if you were to add a large enough volume of high pH water to water below 7 to bring it above 7 is that you would convert any ammonium to toxic ammonia. This could cause deaths, but not from "pH shock".

 

[Macrosill]

Does anyone have some conclusive evidence that small fluctuations in pH have a detrimental effect on fish? I keep hearing about pH shock, but the ony evidence I have seen, points to the contrary.

I do not, I only can go by what I have read here on AA.

A planted tank will have daily fluctuations of pH when the lights are on or off. Since the TDS (Total Dissolved Solids) of the water doesn't change it does no harm.

It is my understanding that ph swings due to the addition of Co2 will not effect fish in a harmful way, it is not the real ph of the water. to get the true ph of the water you would need to leave the water out for about 24 hrs and then test it. This will equalize the gases in the water and give a true reading.

The only possible problem I see, is that if you were to add a large enough volume of high pH water to water below 7 to bring it above 7 is that you would convert any ammonium to toxic ammonia. This could cause deaths, but not from "pH shock".

IThis is the first I have heard of this, not saying it is untrue only I have not heard that before.

Brian

 

[Menagerie]

1st to truly check your tap ph you need to let it sit out for 24 hours to let the gas levels to equalize.

This is very true and very important; although, if you’re not using a huge mug, 12 hours is fine.

Does anyone have some conclusive evidence that small fluctuations in pH have a detrimental effect on fish?

Small fluctuations are not going to affect many fish, but some are very sensitive. I would consider the Balas, Pleco, and Gourami to be fairly hardy and have already shown their ability to survive the pH fluctuations. Having said that and forgetting everything I learned in chemistry, I know the increments on the pH scale are more severe than, for an example, going up one degree F.

Let's get back to the original question: Is there something wrong with the chemistry of my tank, or is does it have to do with my tap water source??
After knowing the outcome of the tap water test and knowing what substrate and decor are in the tank, we will be better able to help you. Also, I will try to find someone who can help us with the finer details of pH, KH and the like.

 

[czcz]

I am not finding anything conclusive in a google search, but anecdotal evidence says it is KH changes that affect fish, not pH, which coincdes with observations from CO2 injected tanks, where the fluctuation in pH is often close to or greater than 1. If rested tap pH has changed from what it was previously, it is of course possible that a change in KH or other buffer by the water supply has something to do with it.

 

[jcarlilesiu]

once again, a stable PH is better than an optimum PH. IF you are really that intrested in keeping your PH at 7 (which I dont see the point in doing) then I suggest you add some crushed coral to your filter media as this is will make it rise and stabilize. Contant changes in PH from chemicals is more hurtful to your fish than just leaving it alone.

 

[TomK2]

Ahh, water chemistry, isn't it fun?

If your tank pH sinks, I strongly suspect that your water has a rather low KH. KH is a measure of the alkalinity, or carbonate present in the water. Water low in KH would be expected to have pH swings, since there isn't enough carbonate in the water to "buffer" the pH. One way to add carbonate to the tank is to add crushed coral to a filter compartment or the substrate. The carbonate in the CC will disolve and help keep the pH stable and higher. Your pinch of baking soda seems to be doing the same thing.

To measure your tap pH, it does need to sit out overnight. I even read one post recently where an airstone was needed overnight to get the water to equilibrate CO2 with the air. But I don't think CO2 equilibaration is the problem here. Usually the tap water has excess CO2 and the pH rises while sitting out, it isn't common for the tap water to be low in CO2 by enough to have the pH lower overnight by absorbing CO2. But this can be checked by you with your quality liquid reagent pH test kit.

So, I think that your tank is low in KH, and a KH test kit is about $5 if you want to see for yourself. The inhabitants in your tank excrete wastes that will lower the pH. Any time you do a water change, you remove the alkalinity that you added with the baking soda, so that the tank can drift lower again, unless you add more baking soda. I can't explain why even a top off would seem to effect your pH, so I am stumped there. I have read that the biofilter bacteria are significantly impaired by a pH below 6.5, so I agree that it might be better to keep the pH above that.

How about checking your tap pH after equilibrating overnight, and think about getting a KH test?

 

[BillD]

An interesting discussion, and perhaps a little away from the thread. However, an acidic environment results in ammonia being in the form of ammonium (NH4), which is nontoxic and much loved by plants. At a pH of 7+, ammonia is present as ammonia (NH3), which is the toxic form. (I hope I got that right). This is where the problem of transhipped fish, dying during acclimation comes from. The CO2 that has accumilated in the bag has resulted in the ammonia being in the form of ammonium. When the bag is opened, the CO2 outgasses or if alkaline water is added, the resultant pH change causes the ammonium to be converted to ammonia. The result is often dead fish. A number of years ago I had occasion to talk to Joe Gargas, who was a regular contributor to FAMA magazine. At the time I spoke to him, he had taken the position of director of R&D for Wardley. He related an experience to me, wherein, he had been asked to consult on a die off problem in a petshop, that occurred after every water change. He discovered that the problem was as described above. They were adding alkaline water to acid water in heavily stocked tanks, and the resultant ammonia spike was killing the fish. That is the only described case i am familiar with, although I did know of the pH/ammonia/ammonium relationship. It was from him that I first heard the term TDS, and it's importance in water chemistry, as it relates to aquariums. Since then, I have read an article on the "pH shock myth" which I neglected to bookmark. In that article, which described studies where large pH changes were shown to have no effect on fish if the TDS of the water remained the same. I haven't checked the pH of my tanks for a number of years now, but I think I will, now out of curiosity. My tapwater, is usually around 7.4 to 7.6, but in the past always rose to 8 after it was in the tanks. I could find no logicaal reason for this, unless concrete dust was getting into the tanks. Since I was having no problems breeding the variety of fish I kept (angels to Africans) I never gave it another thought, but, rather, just accepted it. I change no less than 50% of the water, and often more, and have not experienced any problems related to it.

 

[Dan06]

Hey! Wow, I really enjoyed all the indepth posts, they really make for some great information.

Well, I expanded on my PH test, I used 3 seperate gallons, 2 untreated and 1 with dechlorifyer.

Both untreated read 7.0 ten minutes after pouring. The treated gallon read 7.0 (dechlorifyer was used).

24 hours later and the 2 untreated gallons dropped down to 6.2, the treated gallon dropped to 6.2 also.

So, it appears to me that the water is coming from the tap at 7.0 and quickly drops.

 

[Menagerie]

Really, your tap water has a pH of 6.2 once the gases are allowed to equilibrate. I would do as TomK2 suggested and also test the KH. You may find it harder to keep the larger tank (once cycled) at a pH of 7 with baking soda. Another way to raise the pH is to add calcium carbonate to the substrate or filter media. I have used this method and it worked nicely.

 

[Dan06]

I agree, the baking soda has been a really cheap and easy fix for my 30 gallon, but like you said, when it comes to keeping my 55 stable, I'm definitely going to have to find another way to do this. Hmm

 

[Menagerie]

I found what I was looking for! Raising my PH for Chiclids? is an archived topic that deals with raising pH, which will be helpful for your larger tank. Please ignore when I mention pH in a bottle, as I must have fallen out of a tree that day.

 

[TomK2]

I think pure water has a pH of 6.7 or something like that? I can't remember the exact 6 point something level. It is not a completely nuetral pH of 7.0 because pure water will absorb some CO2 from the atmosphere (the atmosphere has about 2 or 3 ppm of CO2?), and the pure water will then be lower in pH. So, if your tap pH is 7, and it has no CO2 in it, it will absorb some CO2 and the pH will lower.

My bets are that you have a very, very, very low KH, and your waters pH goes down if it catches you looking at it!