pH issues

[dogdoc]

I'm having a hard time regulating the pH in my 16 gal tank. Tap water is about 7.0 and I would like to keep the tank there as a compromise between the mollies (who like 7.2) and the tetras (who like 6.8). I have had the tank for about 2 months now and it is fully cycled. Ammonia is 0. Nitrites = 0. Nitrates = 5. I do (at least) weekly 25-30% water changes, and feed once a day.

My problem is that my pH wants to climb. I have used pH down, and even seachem's neutral regulator, but after about 2 days, the pH is at 7.2 and continues to go up from there. I do have a GH and KH test on the way but right now, I can't test those.

Filters are an aquaclear 20 and a penguin 100 biowheel. Should have about 200 gph flow roughly.

I just hate constantly adding chemicals to the tank to try to regulate the pH. Anyone have any ideas on why it wants to climb? and what I can do to stop it?

 

[JNevaril]

Get rid of the chemicals.

The amount of filtration really wont help a pH issue.

What kind of substrate/decorations do you have?

Many rocks and gravels sold for use in the tropical freshwater tank contain minerals that increase the pH and hardness. If you don't want the pH to increase, ask your dealer for inert substrates and decor.

Do you have plants? Does the tank get sunlight?

Photosynthesis can also increase pH. If the tank or pond gets lots of sunlight and contains loads of plants or algae, the pH can get very high in the day.

Why can't you reduce your pH? Here's a thought...

It is difficult to reduce the pH of your water if the KH (carbonate hardness) is too high. The KH provides a buffer to acids and prevents them from decreasing the pH. Some carbonate hardness is important, otherwise the pH will drop as acids are produced in the tank.


Adding liquid or powdered products to increase or decrease pH is rarely a permanent solution. The majority of aquaria have a fairly high KH which provides a buffer to acids, for example.

Adding these products could cause potentially stressful fluctuations in pH. I avoid using them where possible.

What is the safest way to reduce my pH?

Because a high KH reduces your chances of keeping the pH down, start off with RO water which has a low mineral content. Add a pH-reducing acid, such as API's pH Down, until you reach the desired mark. Replenish hardness with a mineral supplement.

 

[JNevaril]

oh----how many fish are in that tank?

 

[JNevaril]

p.s. ---what is the ph of your tap water?

 

[dogdoc]

tap water pH is right at 7.0. Tank has 4 neons, a black molly, a phantom tetra, a black-skirt tetra, 2 cory cats, and a clown pl*co. It does not get any direct sunlight. I also have a little anacharis plant in there. Gravel is some bright pink and purple stuff (actually my daughter's tank) that I got at Petsmart. Also have a fake palm tree, a treasure chest, and a piece of fake coral. The palm tree is coming out soon as it is losing some of its paint. It will be replaced with a piece of driftwood that should arrive with my KH/Gh test kit.

What type of mineral replacement do you recommend for RO water. I got some distilled water for one of my last water changes. I was amazed that it tested out at about pH 6.0. Can that be right?

 

[JNevaril]

Hmmmmmmmm.

Seems to me that you may be overstocked for one.

The molly should be in brackish water.... 1/2 way between fresh and marine. It's a seemingly simply system...until you put one together...and see how much marine salt is.


A pleco will outgrow that tank soon...they are VERY LARGE fish, and no fish holds to the 'it will only grow as big as the tank' theory.

Possibly part of the problem could be from the paint flaking off of the decoration....as well, as a possibility of poisoning your water...

For RO water, to replace mineral content, for your tank, I would use Aragonite (sold for reef tanks), coral sand or tufa rock can all be added to help boost the pH and hardness of your water and keep it at a stable level.

You may need to adjust the pH of the water and add buffers prior to adding it to the tank to minimise problems with fluctuations, especially if you make large or frequent water changes.

I would also NOT put the driftwood into your tank if it is real driftwood. The tannic acid within real driftwood will, without proper preparations, make your water into 'black water'. Even if it is cured, it WILL slowly but surely LOWER YOUR pH from the Tannic acid!!

Another thing....if the fish are not 'suffering' from the pH coming from your tap, don't stress yourself out by trying to adjust the pH. most fish will adjust just fine.

the only thing i'd worry about now is that the tank is overstocked. in my opinion.

 

[JNevaril]

p.s.

distilled water is different than reverse osmosis water.

RO is only filtration,Distillation means purification.

Distillation removes things based on their relative boiling point.

Reverse Osmosis removes things based on molecular size.


Distilled water is PURE Dihydrogen Monoxide. H20. Aqua. Water.

Reverse Osmosis has FEW trace minerals left in it because SOME particles can pass through the filtration system.

WHY reverse osmosis water is reccomended over distilled, I don't know.

Personally, I don't think it matters, but I use R/O, because that's what the closest store sells.


Unless someone can prove to me why one is better than the other, I say use whatever is closest to you...

 

[Orion]

I have rarely seen things sold at a LFS that will change the chemistry of water. And the few times that I have, it has been labeled as such.

Using chemicals to alter a tanks PH is normaly not a wise thing to do. Keeping it stable is much better for the fish your keeping. You say your tap water is 7.0, let some sit out in a bucket with an air stone in it for 24 hours, and test it and see what it is then. Good chance that you will find that it has risen from what the test reads right out of the tap.

I've never heard that photosynthesis itself can raise the ph? Where did you get this information from JNevaril?

Also the clown pleco will be fine in that tank as long as its the only pleco in there. Clown pleco's don't get larger than 4".They are very teritorial with other pleco's, and will kill them if they can. Driftwood is a necessity with clown plec's, as they need wood fiber in their diet. I've never seen driftwood lower ph in a tank more than a few degree's once cured well.

The only thing in your tank that I see off hand that could be raising your pH is the piece of coral. If it is the culprit, then you'll most likley find that your kH (alkalinity) is very low.

Adding distilled water can and will lower the ph of the current tank. Depending on how much you added when you changed the water depends on if the test result is correct or not. Majority of tropical fish will do fine in about any water. The most important thing to remember is to keep it stable.

 

[JWright]

If your pH is less than 8.0, forget about it. Your fish will be fine. A stable pH is _much_ more important than a "proper" pH.

~JW

 

[dogdoc]

Even the coral is one of the fake resin ones, so I don't know if that will still do it. When my order arrives from big al's this week, I will check the GH/KH, and put the driftwood in to replace the palm tree.

I know that I'm a little overstocked. Since I am new to this I took a lot of advice from the LFS. They told me that the cory's and the pl*co didn't count towards stocking density. Anyway, I have it overfiltered, and I do my water changes religiously, so my parameters all stay looking great except that darn pH.

I have a feeling that I may get my own tank (this one actually "belongs" to my 5yo daughter). And I may move some of the inhabitants to the larger tank when that happens.

Thanks for all the advice.

Mike

 

[Leopardess]

As mentioned before:

A stable pH is far more important than some specified "target" pH. In fact, to a large degree, the pH's that your fish "prefer" is completely arbitrary. Those values are based off of the native habitat of the fish. For example, in the wild, neons live in tha amazon where the water is soft and acidic. So, people say they "prefer" soft, acidic water. However, most of the fish we purchase are not wild caught. Instead, they are farm raised and have never even been in their "preferable" (ie native) conditions. Plus, the fish you buy have been sitting in your local tap water at the store.

Chemicals are a huge no no as far as pH. And as Jwright said, unless it's climbing to 8.2 or more....it's not a "bad" thing.

Some species do require softer, lower pH water to produce viable spawn, but unless you are breeding that is of no concern.

I also was unaware that photosynthesis raises pH. The only justification I can see is that plants are photosynthesizing and thereby producing oxygen. The process of which extracts co2 from the water (co2 having the property of lowering the pH). It becomes a matter of how much co2 is in the water...which relates more to the lowering of pH than the raising of it.

On a side note - and please don't take offense if you already know this - but Jnevaril, there is an edit function on each of your posts so that you can edit information in without making multiple posts.

Test your tap water in the way that orion mentions. Let it sit overnight (aerated if possible) and test it again.

 

[dogdoc]

When I was first cycling this tank though, and wasn't really paying attention to pH, it got really high on me. I think it was around 7.8-8.0 before I started to try to counteract it. We lost an otto. My daughter was unhappy. Maybe I will not mess with the pH any further, and see if it climbs above the 7.2-7.4 level again. Just trying to be a responsible new aquarist.

 

[discus4everGrl]

it's good that you are trying to do the right thing. Glad you came here to ask....

 

[dss2004]

I have Cardinal Tetras in a Q-Tank with a ph of 8.2 going on 3 weeks now. I haven't lost one. Keep the water clean and stable like everyone else is telling you and everything will be great. You should consider yourself lucky to have such a natural neutral ph!!


EDIT: Dogdoc and not to worry your fake resin coral won't be affecting you ph. Sometimes chemicals put into the water cause the ph to do wierd things. Once you follow Orions advice after 24 hours with the airstone all of the chemicals should dissipate and you should have a stable reading!!

Good Luck

 

[JNevaril]

orion--- http://www.fishdoc.co.uk/water/pH.htm

about 1/2 way down.

 

[Orion]

The idea is correct, but the application doesn't jive for me. I just don't see it being such a huge factor in pH swings, or even slight changes.

I just don't think the amount of Co2 given of by respiration or photosynthesis is actualy going to be enough to make the wild ph swings that the article claims, or even small ones in our tanks at home. At one point in time I was using three two litter bottles of DIY Co2 injection at the same time and all that Co2 only droped the pH one whole unit. And I have soft water to begin with.

Like I said, I understand the reasoning behind this, but when put into practice, I don't buy it. Then agian mabey it was there point to make it a big deal and blow it out of perspective.

 

[JNevaril]

hmm.

I guess it is all a matter of perspective, as to what a 'large swing' in pH is.

On a logarithmic scale, such as the one that the pH scale is based on, 1 unit is 10 times more acidic/alkaline than the next, so a 1 unit change would make me wonder what is making my water become 10 times more acidic or basic.

 

[R0UNDEYEZ]

Orion, I have been reading a book called "Ecology of The Planted Aquarium" and they talk in there about photosynthesis raising the PH as well. However, it talks about balancing factors in the aquarium.. they have a column of things that go on in your tank that raise the PH and things that go on to lower the PH most of the things are constantly occuring and the point of it being that if you notice something amiss with your PH, something isn't in balance. I don't think most the time you will see wild swings in your PH since your tank is probably healthy so thats why it sounds like a load of crap to you..

I copied the little chart for you if you were interested.

Sorry that I kinda hijacked the thread... I was just reading about this exact thing lastnight and I found it interesting

 

[Orion]

That is a neat chart Roundeyes thanks.

And sorry if it seems like I'm saying that the idea is crap, as its not. That blurb was poorly writen, with little to no further explaination of the why behind it (at least not in the part I read).

 

[dogdoc]

An update for you all. Just got my GH/KH test, and tested the water in the tank tonight. Both KH and GH levels are at about 5 degrees. Is this an acceptable level for a tropical community tank?