PH Question ???? - Tropical Fish Keeping - Aquarium fish care and resources
LinkBack Thread Tools
post #1 of 4 Old 08-25-2010, 08:08 PM Thread Starter
New Member
PH Question ????

I have a 90 gallon tank with a built in overflow and wet/dry filter system. I have regular natural color gravel and quite a few artifical plants and Several large pieces of real drift wood one about a foot in diameter and an inch thick with lots of holes in it that has been in water in aquariums several years. I have about 40 Small fish Tetras, Mollys. Gourmis and Plattys. I do not over feed at all. Water changes every Monday about 30%. The tank is free of algea.
My question is my tap water PH is around 6.4. The tank PH is 7.6? Is this normal? I would like it around 6.8. I hate to start buffering water. My fish are fine , but would like a lower PH. Some of the Rummy nose Tetras like a lower PH. Any suggestion on this PH gladly accepted. Thanks
woaussie is offline  
Sponsored Links
post #2 of 4 Old 08-25-2010, 08:19 PM
New Member
marhlfld's Avatar
IMO, your pH is just fine. Apparently your fish think so too. Don't start messing with pH or you can have serious issues. I'm not sure how your tap water can be lower than your tank water, if you are using tap water to fill your tank. Driftwood softens water, but won't lower pH from what I understand. It has something to do with the amount of dissolved limestone. As I understand it, some rocks or coral in the tank can raise pH. Someone with more knowledge in that area would have to chime in.
marhlfld is offline  
post #3 of 4 Old 08-25-2010, 09:41 PM
MoneyMitch's Avatar
There is definitely something IN the tank that is raising the ph, the driftwood being so many years old proply isnt leeching as many tannins as it used to. i would scoop out a small amount of your substrate and put it in a cup or something where it can completely dry out. after its dry pour some vinegar over it and ho,ld it to your ear. if you hear the slightest fizz then thats whats causing the ph to raise. Inert material will not fizz at all when vinegar is poured onto it so you can test pretty much everything. About the ph buffing, From me personal experience its a pain in the rear. Every time you w/c you have to condition the water and monitor your ph like every few days depending on your gh/kh. But if i were you which im not i wouldnt mess with the ph seeing how the fish are happy as is.
MoneyMitch is offline  
post #4 of 4 Old 08-25-2010, 11:41 PM
Byron's Avatar
MoneyMitch is correct, something in the tank (or possibly some media substance in the filter?) is leeching calcium into the water, and this raises hardness and pH. All else being equal, a tank will gradually lower in pH as the water acidifies, depending upon the KH of your source water (tap water). The higher the KH the more it buffers pH preventing fluctuations. With a pH of 6.4 in the tap water I would expect the hardness (GH and KH) to be very low, though it sometimes can be different.

That said, to explain why, now to what if anything you should do. Livebearers (molly and platy) need harder basic (alkaline) water. The 7.6 is [perfect, and as mentioned above, this is probably being caused by something calcareous so the hardness of the water will be higher than out of the tap too. Fine for livebearers. But not for rummys.

Rummynose tetra should never be housed with livebearers because their preferences in water are too different. There are three species of rummys, the most common now is Hemigrammus bleheri. If you check our profile of this fish (click on the shaded name in posts, or use the second tab from the left in the blue bar across the top) you will see it recommends a pH below 7 and preferably below 6.5. The habitat water pH as stated there is 3.7 to 5, and I have this from Heiko Bleher who has explored the Amazon region and discovered hundreds of fish including this beautiful species as it mentions in the profile. And all fish are wild caught, so maintaining this fish in basic hard water will be detrimental over time. The result will, at best, be a shortened lifespan, and could be worse. Calcium deposits build up in soft water fish and block kidneys, all sorts of problems. Water parameters are very important for wild caught fish.

If it were me, I would decide on a soft acidic water fish tank or a basic harder water fish tank, and proceed accordingly with suitable fish, re-homing whichever to another tank or the store or another hobbyist.

Byron Hosking, BMus, MA
Vancouver, BC, Canada

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian. [unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]
Byron is offline  

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Newbie Question (Feeding Question) mikedb1972 Beginner Saltwater Aquariums 14 07-16-2010 05:18 PM
a lighting question and a tank question beetlebz Freshwater Aquarium Equipment 2 12-12-2007 10:14 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome