# Why would Ph go down?



## Calmwaters (Sep 2, 2009)

Hi everyone. This weekend when I checked my water in the 44 gallon the ph was 6.0 it normally runs around 7.2 everything else read normal but the ph drop confuses me. Should I worry about it or just let it be? All the fish seem to be happy and acting normal.


----------



## MoneyMitch (Aug 3, 2009)

if everything looks well you should be ok. do u have driftwood or peat in ur tank? what substrate and what chems do you use and how often.


----------



## Calmwaters (Sep 2, 2009)

No driftwood or peat in this tank. It does have 3 small real plants. And I do not use any chemicals at all. When I first set the tank up I used Prime and the bacteria by the same company but I have not used in now in about a month.


----------



## MoneyMitch (Aug 3, 2009)

hmm, any chance you can find out your gh and kh?


----------



## Calmwaters (Sep 2, 2009)

I don't have a test kit nor have I seen one any where to test for those. We have well water but I don't know if that has anything to do with it. When it is streight from the tap everything includeing ph test 0.


----------



## MoneyMitch (Aug 3, 2009)

if its well water than chances are you have a high buffering cap which means it would take some serious stuff to change your ph. at this point i caant really diagnose the problem but hopefully someone else will chime in. sorry


----------



## Calmwaters (Sep 2, 2009)

No problem. I did not do the water change because I figured that would lower the Ph even more which I don't think would be good for the fish.


----------



## MoneyMitch (Aug 3, 2009)

well up north here in ohio our water is naturally hard. (i get hard water stains in my house) dont know if you do or not i just thought of something too, im assuming you have a water softener that your tap goes through. The way my hosue is set up all the faucets IN the house go through my softner while the outside hose does not. i have africans which prefer hard water with ahigh ph. maybe try testing your outside thing and get back to me.


----------



## Byron (Mar 7, 2009)

Calmwaters said:


> No problem. I did not do the water change because I figured that would lower the Ph even more which I don't think would be good for the fish.


Amanda, if your tap water is pH 7, doing a partial water change would raise the tank's pH slightly (from 6 to maybe 6.2 or 6.4) which is not a problem; mine do that every week. However, the real issue is finding the reason the tank is 6.

MoneyMitch is on the right track with the hardness issue, but I'm suspecting the opposite is the case--your well water is probably very soft and thus has no buffering capability. My tap water is like that; GH and KH are 0 or at most 1 ppm, and pH is 6.8.

When an aquarium has been running for a few months, as you indicate yours has been, the natural biological processes will cause the water to slowly acidify and the ph will drop. If the water has a degree of carbonate hardness (dKH) that carbonate hardness will act as a buffer and the pH will not lower much if at all. At some point though it may, when the buffering capability is reached, and then it can crash (the pH). However, depending upon how high the KH is, regular partial water changes will normally keep the tank pH stable because they replace a percentage of the water with fresh water having the specific KH.

If your water has very little or no KH--and well water could be basically rain water (which is always acidic) in some areas, as opposed to water from springs running over mineral beds--then the ph will slowly drop as the tank matures. The weekly partial water changes will help to keep the pH up and slightly stable, but as there is no buffering KH this is risky.

My solution in such a case is to place a small amount of a calcareous material in the filter (or tank), such as dolomite, crushed coral, marble chips; limestone rock also works but much slower. I use canister filters, so putting a nylon bag (made for filter material, you can get these in fish stores) with some dolomite gravel (you can buy this from fish stores, people with marine tanks often use dolomite gravel) in one of the filter baskets with the media works best; you can also use crushed coral gravel, or marble chips. These materials slowly leech calcium into the water stream as it flows over them, slightly raising the hardness of the water and thus the pH. It doesn't take very much, I have about half a cup in my filters on each tank and it adds about 2 ppm KH to the water that is 0 KH out of the tap. In 12 years, this has kept the pH in my tanks from dropping below 6. The dolomite needs replacing maybe once a year.

You could get an API test kit for hardness (that includes both GH and KH, they also have them separately but both KH and GH are good to know) or take a sample of your tap water to the fish store and ask them to test the KH and GH. KH is the more important for the buffering capability, but the GH is useful to know. Once you know this, you will know what action if any to take.

Before speculating on other possible causes, I would suggest testing the water as this is usually the answer. In the meantime, continue the normal weekly pwc, 30-40% max, as letting it go without a pwc will probably allow the pH to continue lowering. On no account attempt to adjust the ph until you know the hardness; fluctuating pH greater than .4 can seriously affect some fish; a stable pH, whatever it is, is preferable. There is a normal diurnal fluctuation of .3 to .5 in all planted aquaria between daylight (pH rises during photosynthesis) and night (pH falls) and the fish have no problems. But sudden changes in short periods can be fatal.

Byron.


----------



## Calmwaters (Sep 2, 2009)

Thanks Byron. My tap water when it first comes out has no reading as far as ph, amm, nitrate, or nitrite. I will go by the better of the LFS this afternoon and see if there test will check the things you need to know. I do have a piece of rock that I purchased to raise the Ph in the tank when I had thought about doing a ciclid tank. Maybe if you think that is what I need I could either break it into small pieces or put the hole piece into the tank it is 2 pounds so I do not know if it would be big enough to raise the ph or not.


----------



## Byron (Mar 7, 2009)

Calmwaters said:


> Thanks Byron. My tap water when it first comes out has no reading as far as ph, amm, nitrate, or nitrite. I will go by the better of the LFS this afternoon and see if there test will check the things you need to know. I do have a piece of rock that I purchased to raise the Ph in the tank when I had thought about doing a ciclid tank. Maybe if you think that is what I need I could either break it into small pieces or put the hole piece into the tank it is 2 pounds so I do not know if it would be big enough to raise the ph or not.


Let's find out the KH and GH of your water source before you start breaking up rocks:shock:.

Get both if they will, or KH if only one, and get them to tell you the numbers, not "it's normal" or "it's average" or similar, which means nothng.

Don't understand you saying the pH of tap is nothing...must be something.??

Byron.


----------



## Calmwaters (Sep 2, 2009)

I rechecked the tap water and it does come out real close to 7.4 so thats not bad. I don't know why I thought the last time I checked the tap water it did not register anything. I will get the readings you need today when I go on lunch. I would have got it last night for you but I had to work at my second job so I did not have time to go home and then back to the store.


----------



## Calmwaters (Sep 2, 2009)

Ok I got the Gh and Kh numbers. The Gh is 75 and the Kh is around 100.


----------



## Byron (Mar 7, 2009)

Calmwaters said:


> Ok I got the Gh and Kh numbers. The Gh is 75 and the Kh is around 100.


These would be ppm (parts per million) numbers, and thus indicate soft water. The comparable dGH would be about 4 for the general hardness of 70ppm; my tap water is 0 or 1 dGH.

That gives us a better idea. The natural biological actions will lower pH by acidifying the water so I don't think there is a problem. The question is, what ph do you want in the tank? I don't see a listing of fish for this aquarium; if they are fish that naturally prefer soft acidic water (tetras, gouramis, rasbora, catfish, loaches...) you might want to let it stay around 6. Adding a small amount of dolomite or crushed coral gravel to the filter would prevent any lowering, and the partial water changes also. I keep my tanks at 6 by this method. It doesn't take much, and I prefer it in the filter where you can add/remove some easily rather than dumping it in with the substrate.

Limestone rock does not work very well for this, as it is slow to dissolve. Dolomite, crushed coral, and I'm told marble chips are all faster and with small amounts. I only have about half a cup of dolomite in my tank filters (115g, 90g and 70g tanks) and it raises the GH by 1-2 dGH.

Byron.


----------



## Calmwaters (Sep 2, 2009)

Thanks Byron. There are Rasboras, Swordtails, Neons, Playts, Cory Cats, Mystery Snails, and female Bettas in this tank. I can not remember the name of the rock I have but I can call the LFS and they can tell me if you think I might should put some into the filter media.


----------



## Byron (Mar 7, 2009)

Calmwaters said:


> Thanks Byron. There are Rasboras, Swordtails, Neons, Playts, Cory Cats, Mystery Snails, and female Bettas in this tank. I can not remember the name of the rock I have but I can call the LFS and they can tell me if you think I might should put some into the filter media.


The platys and swordtails prefer (and do better in) water slightly basic (alkaline), pH in the range of 7.2 to 7.6. The other fish will be happier in slightly acidic water, pH mid-to high 6's. But they can probably adjust to a slightly basic pH if it is done over several days. And using one of the calcareous rock gravels is the safest way in my view. 

Dolomite gravel is not expensive, and a very small bag will last years. I would get it, and put maybe two tablespoons in a nylon bag in the filter so the water can flow through it. Monitor the ph and if after 10 days or so it is not high enough add another spoon of dolomite. It doesn't take much, and once it starts to act it will act, so go slow. Gravel is better because the smaller pieces will release calcium more effectively.

The above is if you decide to continue with the same fish in the one tank. To be honest, if it were me, I would not keep livebearers with the other fish simply due to the differing water preferences. Both groups will be better, which means healthier, if they are in their preferred water conditions.

Byron.


----------



## Calmwaters (Sep 2, 2009)

Ok thank you for your help. I will get the Dolomite gravel and see how things go.


----------



## MoneyMitch (Aug 3, 2009)

i wish you the best and dont hesitate to post if you are having complications still after a week or two.


----------



## Calmwaters (Sep 2, 2009)

Thanks Money.


----------

