|
| FAQs on pH, Alkalinity, Acidity: Practical
Science
Related Articles: pH, alkalinity,
In praise
of hard water; How hard, alkaline water can be a blessing in disguise by
Neale Monks, Treating
Tap Water,
A practical approach to freshwater aquarium water
chemistry by Neale Monks,
The Soft Water Aquarium: Risks and Benefits
by Neale Monks,
Freshwater Maintenance,
Treating Tap water for Aquarium Use,
Related FAQs: pH, Alkalinity,
Acidity 1,
pH, Alkalinity, Acidity 2,
pH, Alkalinity 3,
pH, Alkalinity 4
& FAQs on: pH/Alkalinity Measure,
pH/Alkalinity Adjustment,
pH/Alkalinity Products,
pH/Alkalinity Anomalies/Fixing,
& Water Hardness,
Freshwater Aquarium Water Quality,
Treating Tap Water for Aquarium Use,
Freshwater Algae Control,
Algae Control, Foods, Feeding, Aquatic
Nutrition,
Disease,
|
pH... measure is a "point", Alkalinity, a measure of downward resistance in
pH, Acidity, a measure of upward resistance in pH.
Principally carbonates and bicarbonates serve ask alkalinity boosters.
Recommended Alkalinity: 10 to 12 dKH or 3.5 to 4.5
mEq/liter or 175 to 225 ppm... |
Abstract Questions from a Freshwater Aquarist
7/31/09
Hello.
<Hi,>
I just have a couple of questions that I couldn't seem to place under
the same category (hence the name). Okay, my first question is
can ph kill fish?
<Yes. Rapid changes alters blood pH, and this turn affects the ability
of the blood to carry oxygen and carbon dioxide around the body. The
wrong pH will severely stress, eventually kill, those fish adapted to
particular pH levels. A Rift Valley cichlid for example will not do well
at pH 6, and will become much more prone to opportunistic infections
than otherwise.>
I recently bought 5 goldfish for my aquarium, I set the bags in the
water for 15 minutes, then netted the fish and put them in my aquarium.
Three hours later (literally) they all died. I checked my water
chemistry soon
after, and the only offending thing I could see was a ph below the
charts (anywhere from 5-5.4, judging by the color) Nitrate: 40 Nitrite:
0 Ammonia: 45-ish Hardness: Moderate Temperature: about 76 at time of
death.
<Goldfish will tolerate pH values across a broad range, at least for a
while, but they do best at basic pH levels between 7 and 8. If your pH
really was as low as 5, then [a] biological filtration wouldn't be
working,
and [b] that low pH could easily have shocked or killed the Goldfish
outright.>
My second question: are store-bought fancy guppies of poor (I
mean very poor) quality?
<Can be. Essentially the question is the same as this: which are hardier
and more long lived, pedigree dogs or mongrels? The answer is of course
mongrels, which, on average, consistently outlive their pedigree
cousins.
Guppy breeders select in favour of certain traits, such as tails of a
certain length, or particular patterns on the body. But they don't
select in favour of hardiness or longevity By contrast, evolution
selects in favour of "fitness", the ability to survive and breed.
There's actually good experimental evidence that supports this. Fancy
Guppies cannot be acclimated to living in seawater, whereas wild Guppies
and "feeder" Guppies
both can. In other words, when breeders create Fancy Guppies, they seem
to throw away some of the genes that made Guppies hardy in the first
place. Now, there are differences in quality of Guppies just as there
are differences in the quality of pedigree dogs. The Guppies you buy
from a pet store were bred to a price, not a quality, and often fish
farms use antibiotics to "support" their fish so that they can stock
lots of them in breeding ponds without being too worried about
healthcare. By contrast, breeders at fish clubs will be taking more
care, selecting the best fish, and looking after each group of fish
carefully, as a labour of love. None of this gets away from the fact
that Fancy Strains are often very inbred, with father-daughter,
mother-son crosses being very common, so even under the best of
circumstances, Fancy Guppies are genetically "weak". But there is a
difference between good quality fish and mass produced fish.>
I've heard that the guppy is supposed to be the easiest and most
enjoyable fish in the hobby, and yet I've also had experience (and read
on other sites) that suggests otherwise, mostly due to inbreeding and
the breeders only selling low-quality fish to pet stores.
<Pretty much. Wild Guppies are astonishingly adaptable, and that's why
they became popular in the first place. Fancy Guppies, like fancy
varieties of most aquarium fish, are much less adaptable.>
My third question is if I breed natural (feeder) guppies with Fancy
guppies, will (some of) the fry be fancy and hardy?
<No; they'll all be "feeder" Guppies, or at least, mongrel Guppies with
a mish-mash of colours. To my eyes, such Guppies are lovely, resembling
the wild-type fish, which are wonderfully variable. The old name for
Guppies, Millionsfish, referred to the fact that there were so many of
them, and every one was different.>
My last question is that I've heard (on this site and others) that
Hornwort is an amazing and under-appreciated plant.
That it eats up Nitrates and Ammonia, looks good, reduces water
hardness, sucks up CO2, puts in O2, increases water ph, and is easy to
keep. How many (if any) of those things are true?
<Like high-fibre breakfast cereals, while it certain does some good, it
isn't a magic bullet that will cure all life's ills! Hornwort, or
equivalent floating plants such as Floating/Indian Fern or Amazon
Frogbit, are great additions to tanks with livebearers. Your Guppies
will nibble at them directly, and also peck away at algae growing on the
roots. Yes, they absorb some nitrate (and even ammonia) at a rate
depending on light
intensity (i.e., growth rate) and yes, floating plants provide excellent
hiding places for newborn fry. I strongly recommend them, but I would
expect them to replace your standard protocols for water quality and
water
chemistry management.>
I'm looking for a beneficial plant to re-place my withering ones (might
help those plants if I turned off/down my air-stones), and then stumbled
across the Hornwort.
<Hornwort does need strong lighting at tropical temperatures. It's less
demanding in coldwater tanks and ponds. In tropical tanks, sometimes
wastes away if the lighting is poor to moderate. Indian Fern and Amazon
Frogbit are, in my experience, a bit more forgiving.>
Hope I wasn't any trouble!
-Koda
<Cheers, Neale.>
Re: What's going on? FW quality 8/7/07
Hi Neale,
<Hello Scott,>
Thanks for the quick response, and sorry to bug you again, but...
<It's fine...>
I agree that the KH and GH is too low, but do not know how to raise them without
adverse effects. Referring to the KH I use to use a phosphate buffer to control
PH and it worked well but also caused hair algae, so I went to just baking soda,
but if I add enough to raise the KH to the level you suggest then the PH raises
to 8.0 and I prefer to keep soft/acid type fishes. (Discus on the way to go with
the blue ram, Cory's and Pleco's.
Silver dollars will go to the other tank.) Even the 7.2 is IMO too high and I
would like to keep it lower at between 6.5-7.0. Any ideas there?
<I personally always recommend against keeping fish in acidic water conditions
unless you have to, e.g., for breeding purposes. There's no real advantage.
Let's look at why. First of all, pH is a mirage. Fish don't "feel" pH. They only
feel the total dissolved solids, since that's the only aspect that impacts their
biology (specifically, osmoregulation). Adjusting pH up or down without first
figuring out the correct General Hardness and Carbonate Hardness is like
painting your motor car black and saying that turns it into a London taxi cab.
So, forget about pH, and forget about buffers. Fish will adapt to a range of pH
and hardness values, and silver dollars for example are fine in slightly
alkaline, moderately hard water. The advantages to keeping them thus are
two-fold. Firstly, water with appreciable levels of hardness (especially
carbonate hardness) resist water chemistry changes. Secondly, the filter
bacteria prefer alkaline/hard water conditions and hate soft/acid water
conditions, so you get better water quality. Finally, all fish prosper best
where the aquarist can do large, regular water changes. Most fish would sooner
be kept at sub-optimal water chemistry values provided those values were
constant (as they would be with regular water changes). Keeping fish are
"optimal" values if soft and acidic won't help if the pH changes between each
water change, as would happen if the water changes were small and the aquarist
had provided no reliable buffering capacity to the aquarium.>
The GH issue is that I use RO Right to reclaim the RO water and although the
amount added does not give me a reasonable GH reading, it does give me a TDS
reading of about 110ppm all by itself.
<Any reason you don't mix RO water with plain tap water? I mix rainwater with
tap water to get soft, slightly acidic water when required and it works
perfectly. I use the ratio 25% tap water to 75% rainwater. You can use a Pearson
Square to figure out the GH or KH of the water you produce by this method. Even
a 50:50 mix should get something with moderate hardness and a neutral to
slightly alkaline pH ideal for silver dollars, Corydoras, etc. The reason I say
mix with tap water is its a cheap approach that combines the ease of large scale
water changes with the buffering capacity present in many local tap water
supplies. My tap water here has something like 20 degrees dH and a pH around 8.>
I have heard that this is a good product, but I too would have expected its
makeup to provide more calcium and magnesium or what ever the test kit tests
for. Another possibility is that the test kit is faulty, but I have already
tried 2 different test kits and have the same readings on each.
<Probably is a good product, but fundamentally fiddling about with buffering
solutions is hard work. Certainly, you should "practise" on disposable buckets
of water to get the exact water chemistry you want before keeping any fish in
it. I repeat, what matters with freshwater fish is *consistency* in the water
chemistry, not what the actual values are. Within reason, fish will adapt to a
spectrum of pH and hardness values.>
As for the cloudiness I did try a water clarifier but that did not work. In fact
it worsened the problem temporarily.
<Odd. One thought might be a diatom bloom. This normally only happens in marine
tanks, and the solution is a UV filter. I'd still tend to opt for breaking down
the tank, cleaning, and returning the fish to the tank once cleaned. See if the
problem happens again. I call this the nuclear option -- a bit like instead of
faffing about with a computer trying to figure out the problem, you just erase
the hard drive and put everything back. In the long run, a time saver.>
I will have to try the vegetables, because the silver dollars hunt out the algae
wafers even in total darkness. I know this because I have a night vision camera
that I watched with after dropping a wafer into the tank in total darkness, and
within 5 minutes or so the silver dollars will slowly zero in on the wafers by
smell or what ever sense they have, and eat them.
(can fish see infrared light? It sure made their eyes glow brightly).
<No, fish can't see IR, though they don't need to. Their eyes are much more
sensitive to visible light than ours, and some can also see UV to some degree.
They also have a very good taste/smell sense plus the lateral line system for
"touching" at a distance.>
Hopefully they will not smell cucumber or if they do will not be interested in
it. I have never fed them such so they may not recognize the smell as food and
therefore leave it alone.
<Worth a shot. You can't overdose vegetables because they contain so little
protein. So sticking half a head of lettuce in a fish tank won't cause anything
like the ammonia pollution of a one extra pinch of flake. I often leave big
chunks of vegetables in my tanks for days at a time. The softer they become, the
more the fish like them.>
How do Pleco's get their protein?
<From vegetables and algae. Because there's so little protein in 1 gramme of
vegetable compared to 1 gramme of meat, Plecs need to forage more or less
constantly, and will usually zoom right in on a meaty treat like a mussel given
the chance. A few Plecs, notably the genus Panaque, can actually extract
proteins from digesting wood something very few animals can do.>
Thanks again,
Scott
<Good luck, Neale>
Water chemistry question 1/8/06
Dear WWM Crew: First, I would like to start off wishing everyone a very
happy, healthy and prosperous New Year. Thank you for your ceaseless and
selfless dedication to making this site what it is. You all have helped me once
in the past and I hope you will help again. My question involves water
chemistry. I have done quite a bit of reading, but I am still somewhat
confused. In testing our tap water, we found that it is a bit unfriendly for
our fishy family members: ammonia 4-8 ppm, nitrite .5-1 ppm nitrate 20-40 ppm,
<... these readings are dangerous for your domestic use...>
TDS 220. We were buying bottled water from the grocery store but that grew old
fast because we have 4 freshwater tanks totaling 245g with a 5th tank (75g
rainbowfish) in the works. We took the plunge and bought an AquaFX Mako 5 stage
RO/DI with chloramine buster attachment (by the way, it is a phenomenal filter,
if somewhat expensive) which gives us wonderfully pure water. I do understand
about reconstituting the water. I understand
it is better to aerate the water for 24 hrs before buffering, and I do somewhat
understand the relationships between pH, KH and GH.
<Good>
I have read here on WWM that a stable pH is more important than an 'ideal' pH
<Yes>
and I understand the reasoning behind it. In my first attempt to make up water,
my parameters are as follows, pH 7.6, 9 DKH and 23 DGH. The pH pretty much
matches the pH in the tanks now, with 2 of the community tanks at 7.6 and the
other community tank and dwarf cichlid tank at 7.4. I am using 1 teaspoon of
baking soda, 1tablespoon of Epsom Salts and 1tablespoon of aquarium salt per 5
gallons.
<Mmm, this is a bunch of Epsom, and possibly too much aquarium salt... I would
dilute this by at least half>
I will be taking another container and split this between the 2 before making
more water to lower the KH and DH, but my question really is: can too much KH
and GH be harmful to fish?
<Depends on 1) the species, 2) what they've been raised in/exposed to, 3) what
you want them to do, and 4) "other" factors... All have some range, tolerance to
change...>
We don't keep Discus, but we do have some interesting fish including a black
Ghost Knife and African Butterflies. I know that some fish like a softer water
to breed in, but we are not really interested in breeding fish at this time.
Also, is it more important to pay attention to the alkalinity for keeping the pH
stable, or treat the KH and GH equally?
<More important to gauge, adjust alkalinity overall in most cases/settings...
the calcium hardness is good to "judge" or keep at about half or so of general
hardness...>
Am I using too much aquarium salt to add back the trace elements?
<Yes... I would use either a good general buffering product (made for aquarium
use) or make one up here. Salts (combinations of metals and non-metals) have
other properties... You don't want to "knock yourself out" trying to avoid salts
altogether (they are present in all waters to a degree), but I would not
purposely add much "back" to adjust your water>
To paraphrase Dr. McCoy: "Dammit Jim, I'm a computer technician not a water
chemist!" Thanks again for any clarity you can offer and keep up the awesome
job.
Thomas N. (Tom) Bilello
<Understood... With the number of gallons total in your systems... I would rig
up a system to "batch treat" your make-up water... engage a calcium carbonate
addition as well as the/a bicarbonate (baking soda)... and likely leave this as
it... Bob Fenner>
Alkalinity & pH 9/20/06
Hi!
<<Hello, Angi. Tom>>
When I measure my pH it is normal for my goldfish (7.5)...but when I test the
Alkalinity it is low (40 - 80 ppm).
<<Okay.>>
What should I use to raise the alkalinity and not raise the pH. I have
Buff-It-Up (which didn't do anything), Stable 7.5, and Alkalinity Buffer (I
think by Sea* something). This has me totally confused (I'm very new at
this). Oh, my water is hard from the tap. If my pH is 7.5 which is alkaline
why would my alkalinity reading be low? I am sooooooooo confused!!!!
<<Easy to become confused by all of this, Angi. Perhaps it would be beneficial
to use the term "basic" rather than "alkaline" to alleviate confusion between
the terms alkaline and alkalinity. (Works for me!) Okay, "alkalinity" is a
measure of a sample's ability to resist changes in pH (downward) in the presence
of an acid. By the very same token, "acidity" is a measure of a sample's ability
to resist changes in pH (upward) in the presence of an alkali, or base. In
simple terms, it's "buffering capacity". Where, on either side of "neutral", a
sample tests on the pH scale, at a given time, has no bearing whatsoever on its
"acidity" or "alkalinity". This is borne out by what you've discovered, i.e.
your sample tested "basic" (alkaline) but its buffering capacity (alkalinity) is
low. Frankly, this isn't a stable condition since naturally occurring carbon
dioxide in the air mixes with water to form carbonic acid. Additionally, there
are other organic acid "dynamics" that take place in our aquariums that compound
the problem. What this means, to you and others in this situation, is that your
pH levels are in a precarious position. (Just what you didn't want to hear,
right?) Hence, you need to increase your alkalinity (buffering capacity) in
order to resist a plummet from a slightly basic pH level (7.5) to an acidic one
(>7.0).
Here's where things get stinky, er, sticky. It simply ain't easy to increase
alkalinity without raising the pH levels. Sodium bicarbonate (baking soda)
provides excellent buffering capabilities due to the "bicarbonate" element but,
if not added very, very judiciously, can drive your pH up dangerously. The
products you mentioned above are, to greater or lesser degrees, of questionable
efficacy. Honestly, I would look to small but frequent water changes rather than
trying to chemically alter your water parameters. In the time that you'll spend
playing around with various "buffers" and "stabilizers" as well as the requisite
parameter tests to ensure that you haven't screwed up somewhere along the line,
you could have, easily, performed a simple water change. In the long run, you
might find yourself acclimating your Goldfish to pH levels outside of the
"ideal" but, many credible sources suggest that you're better off keeping your
fish at your tap water parameters than to "artificially" rearrange them.>>
Thanks for you time.
Angi
<<Hope this helps somewhat, Angi. Best of luck. Tom>>
Re: Alkalinity & pH 9/20/06
Thank you sooooo much Tom!
<<Oh, stop. You'll make me blush.>>
Frequent water changes is exactly what I'll do (I sort of enjoy it anyway).
One little question....when I'm doing like a 50% water change and gravel
cleaning, would it be best to remove the fish to a bucket of the original
aquarium water?
<<Angi, you don't really want to go with a 50% water change. That falls into the
"massive" range. Keep it to about half of that and you'll be "golden".>>
They are constantly sucking on my arms!! LOL!!!
<<They like you, Angi! Nothing like some good fish kisses. :)>>
I have 2 tanks (29 gal with 2 Oranda -- about 4" body size not counting fins)(40
gal with 2 moors and 2 Ryukins --- about 2" body
size). I've decided to get rid of the gravel in both tanks. It's a real pain
trying to feed them because the only ones who see the food coming are the
Ryukins. The rest have to try to get what has fallen between the gravel (1/2"
gravel)....so the gravel is outta of here!
<<Oh, they'll scavenge, anyway. Won't be as much fun for them but, it'll be a
whole lot easier on you!>>
Take care and thanks soooooooooo much again!!!
Angi
<<You're most welcome, Angi. Tom>>
Re: lowering ph in planted tank
7/27/08
Neale,
Well, I got a RO/DI unit (for a smoking good deal, so not sweating the cost, and
have a use for the runoff H2O), the output of which is currently 0 TDS, 7.0 ph,
and alkalinity is somewhere between 0-10 ppm. Just RO is about 16 TDS,
alkalinity is same, ph is same.
<All sounds promising.>
My tap water is 420 TDS, 8.0+ ph (kit doesn't go above that), 130ppm alkalinity,
and 210-220 calcium.
<Standard issue "liquid rock"!>
I mixed 50/50 tap and RO+DI, and I got 60-70ppm alkalinity, but the ph was still
8.0+
<It would be; acidity is created by the presence of acidic chemicals, not by
reducing hardness. There's a complex thing behind pH involving the relative
proportions of things that raise pH (alkaline chemicals, such as bicarbonate
salts) and things that lower pH (acidic chemicals, typically organics such as
tannins). What softening water does is reduce the abundance of the alkaline
chemicals, so that smaller amounts of the acid chemicals will lower the pH.>
I want to get roughly neutral ph with 70ppm alkalinity (to be safe...as you say
55ppm or so is a minimum target).
<Sounds fine.>
Seems like my main option here would be RO+DI and a neutral buffer to get my
alkalinity up. Am I heading down the right track?
<Yes, pretty much. I'd be using your 50/50 soft/hard water for starters, and to
be absolutely honest not messing with pH just yet. I'd want to see how the
background acidification of the tank affected pH between water changes (testing,
say, ever 2-3 days). Once I was confident that pH was stable, I'd then look to
using either carefully controlled amount of peat granulate in the filter to
increase acidity or else using a pH 7 or pH 6.5 buffer salt as required. I like
the Sera Peat Granulate; it's concentrated, so you can start off with tablespoon
or three in a media bag, pop it into the canister filter, and then see what
happens with pH across the next few days, checking pH daily. The water will turn
brown of course, which may or may not be a good thing depending on your needs.
Commercial pH buffers will "fix" the pH and keep water chemistry within a very
safe range provided they are used correctly. They are more expensive than peat,
but perhaps easier to use. But remember: pH itself doesn't matter much, pH
stability does. If your aquarium is medium-hard to slightly soft in terms of
hardness, it's already "optimal" in terms of fishkeeping. So medium-hard water
at pH 7.5 would be fine for a wide variety of fish without any further fuss.>
I am also trying to figure out how to mix some tap water in to get the calcium
and some
alkalinity help. Any suggestions on ratios?
<Experiment, and see what you get. A 50/50 mix is ideal (as well as cheap to run
in the long term) so I'd start there and monitor/adjust pH afterwards. Don't get
dazzled by the idea there's some "optimal" pH because there isn't; instead
understand the goal, creating water similar to the wild, by reducing carbonate
hardness and adding organic acids such as tannins.>
Thanks, as always, for the help.
Paul
<Hope this helps, Neale.>
pH in 29 gal FW
Hello!
First of all, I've really enjoyed your site. Very informative.
<Ah, good>
I have recently moved my 29 gal FW, and completely started over. I cleaned all
the gravel and decor and the tank. I let the system sit for a week before adding
fish. I have only added a barb and a diamond tetra and a Cory catfish. I am
familiar with "new tank syndrome" and thought I knew what to expect. Even before
I moved the tank, I was having problems with the pH going down. It was staying
around 6.2 - 6.4 for the last 4 -6 months.
<Sounds like your source water is lacking in sufficient alkalinity... you can
easily add alkaline reserve... with simple baking soda, sodium bicarbonate, for
instance>
I have all plastic plants and rocks, a sunken ship and one ceramic (?)
decoration. I have had this aquarium for over two years and have just started
getting the pH drops within the last 6months. I thought that starting over might
help but it has only been 3 weeks and the pH has dropped already from 7.2 - 7.4
(out of the tap, treated) to 6.2 - 6.4. Ammonia levels are normal.
<Hopefully zero concentration of ammonia>
The drop occurred after I put the fish in. It has been so long since I have had
a "new" aquarium, I can't remember all. I knew to expect an increase in ammonia
and nitrates, but don't remember pH going so low. Am especially concerned
because it was happening before I moved the aquarium. I don't think it is our
tap water because I have a 10 gal and a 5 gal that are doing just fine.
<Mmm, they likely have some basic (as opposed to acidic or neutral) materials in
them... like natural gravel, rock, other decor that is buffering the pH>
I usually do approx. 10% water changes every 1 -2 weeks in all tanks, but have
not started water changes in the 29 gal since moving it. (wanted to give the
"good" bacteria chance to grow)
<Yes, good idea>
The fish do not seem to be stressed or unhappy, so I haven't done anything to
change pH levels. I don't see much of the Cory, but then I never have. These
fish are all over 1.5 years old. Should I just leave the pH alone and start with
water changes? Should I go ahead and add more fish?
<I would hold off on the new fish for a few more weeks... and consider either
getting an alkalinity test kit (please read on the WWM site re the relationship
between pH and alkalinity), or add about a tablespoon of baking soda (mixed in
ahead of time in tank water) every day till you see your pH starting to be
nudged upward to where you want it (about neutral, 7.0 or so). The baking soda
is very safe added at this rate, and by keeping good records you can learn about
how much you may want to add during your periodic water changes.>
Thanks for your help
Leigh Walker
<You are welcome my friend. Bob Fenner>
Evaporation Chemistry
Hello,
A quick first question or two from a long time reader.
<Welcome back>
If water lost to evaporation is mostly pure water then why do I need to buffer
the DI water I use to replace the lost water? Don't the buffers stay in the tank
when water evaporates?
<Mmm, they get "used up"... very basically (bad pun), the overall reactions in
closed systems are reductive (as in Redox)... they tend toward making the water
more acidic... in effect exhausting the alkaline reserve>
Second, how do I determine how much buffer to put in the DI make up water? I'm
using Seachem Marine Buffer per a recommendation in one of the FAQs.
<Best way is to measure your water (new) and try adding your buffering product/s
with testing... per your particular livestock, desires for GH, dKH...>
Thanks for providing such a terrific service to all new folks.
Regards,
Jim C
<Thank you for your participation. Bob Fenner>
pH change & Dead Guppies 3/16/04
I had an excruciatingly painful experience last night with my guppies! I
had put a bowl with the water from the aquarium itself inside this aquarium. So
it was the same water - I thought. I put fish in it that were pesky or causing
trouble to the community and so it was kind of like a "jail house" for bad
fish.
<Hmmm, that's what breeder nets or quarantine tanks are for.>
I had this bowl inside the aquarium for at least a week, maybe two, with a male
platy who kept trying to "eat" my albino cat fish. I was afraid he'd eat him
alive eventually, so I put him in there.
<Kind of odd... My Cory catfish can hold up against dwarf puffer teeth.>
Then there was a female guppy which had given birth to about 6-7 babies and was
being hotly pursued by about 4 male guppies, so thinking she needed a rest, I
put her in there. I noticed that she had scoliosis, so wasn't expecting her to
fully recover.
Then about two days later, I found her dead in the bowl. I thought she'd died
from the skeletal deformity she'd had, or something related to the stress from
giving birth.
<Probably tuberculosis, extremely contagious to humans--http://reefkeeping.com/issues/2003-07/sp/feature/index.htm>
The thing that got me yesterday was this: I saw these 4 male guppies had begun
to harass the other female guppy and were relentlessly chasing her, so I put all
4 of them inside the bowl to "do some time for bad behavior," and to give the
female guppy a little rest. Then, to my amazement, about an hour later, I was
going to turn off the light to go to bed and I looked and saw that ALL 4 MALE
GUPPIES WERE LYING DEAD IN THE BOTTOM OF THE BOWL!
I fished them out, and thought I noticed one's tail had disintegrated, but I'm
not sure about that. There others' were all intact, but they were all dead. I
then checked the ph in the bowl and found the ph to be acidic, about 6.2 or
so. The water in the main aquarium was at about 7.0 or maybe 7.2. So that's
about 1.2 points difference! I didn't think the water would be that variant
since it was the original water from the aquarium, but I hadn't tested it since
I put it in there about two weeks ago.
<If there is no water flow getting into the bowl (like it would in a net
breeder) then the ammonia & waste produces by your fish will build up in there,
causing the pH to drop. Your fish probably died from ammonia poisoning.>
Meanwhile, the original platy is still alive inside the bowl with the acidic
water and is showing no signs of stress. Why, then did all 4 guppy males die
within one hour or so after being put into the bowl??? The only possible
explanation I can think of is that the ph change was too drastic for them! Is
that a possibility? I thought they would be maybe stressed out by such a
change, but not DEAD!!! Please advise. Is there some other possibility that I
am not able to see?
<I'm afraid your platy is doomed in that bowl also. Get a breeder net, or set
up another tank for quarantine or to keep your more aggressive fish in.>
Thank you very much for your thoughtful advise!
<You're welcome & good luck. ~PP>
Leslie Wilson
pH in freshwater tank
Hi, I had been using some cheap, not very accurate ph strips which told me
that I had ph between 6 and 7. Last night I received an order of supplies
including some 5-in-1 test strips, called "scientifically and medicinally
accurate" on the label. They place the ph of the tank (and our tap water) at
closer to 8 or even a little higher. Since the tapwater and the tank are the
same ph I can only assume my tank has always been at that level. As for the
other readings, my water is listed as slightly over ideally alkaline (KH),
between 180 and 300 ppm (but not as high as 300), between 150 and 300ppm total
hardness or GH, 0ppm nitrite, and below 40 ppm nitrate.
<<Hello. Perhaps you can take a sample of your tank water and tapwater to your
LFS and have THEM test things for you, to see which tests the results compare
to...for all you know, the old test strips may be the good ones.
Impossible to tell unless you test these parameters with yet another brand of
test kits. Two of them should match.>>
The fish all seem perfectly happy in this environment and I don't want to really
mess with it unless I am sure I am going to be able to make a permanent
change. I understand that slightly acidic water is generally better for
freshwater tropical fish?
<<Which species? "Freshwater fish" like African cichlids need a pH of 8, while
freshwater fish species like discus need a pH of 6.5. Yet both are members of
the family Cichlidae. Same goes for all other species of fish, you need to
research EACH species you want to keep, and try to choose species that have the
same requirements, to keep together. Many fishkeepers have more than one tank,
with more than one pH, keeping their various species happy. Also, remember to
note the feeding requirements of the species that interest you...it can be
difficult to feed slow-moving herbivores that are being kept with fast-moving
omnivores...
Also keep in mind that the pH of your tapwater can change seasonally, and will
also change after being aerated overnight...your tapwater can go from 8.0
straight from the tap, to 7.6 after being stored in a Rubbermaid bin
overnight...same water!>>
I have currently harlequin and scissortail Rasboras, Cory and Otos, and am
planning to get ghost catfish, cardinal and Rummynose tetras, and a Gourami or
two over time (especially as I am able to get a good population of live plants
going).
<<This sounds like a fine mix, most of these species will do well if you keep
them in a pH from 6.5 to 7.5.>>
Am I going to have to adjust the tank for these fish? if so what do you guys
recommend as a permanent, long term solution?
Thanks, ~Anna
<<If, indeed, you feel you need to lower your pH and soften the water for your
fish, the easiest way is by using peat moss, sold at your LFS. But first
double-check your pH with the LFS, like I said above. If the pH is still 8.0
from the tap, then store some overnight and test it again to see how far (or,
IF) it drops. If you do these things and the tapwater still tests at 8.0, you
can (as I mentioned earlier) store your extra water in a bin, run a powerhead in
the bin to circulate the water, and keep peat moss in the powerhead media
basket. It is quite easy to change your peat moss this way, and you will always
have water change-water at the ready...the amount of peat moss you will need
will depend on how far you want to drop the pH down.
You may only need a small bit, you may need a lot. Depends on your source water.
Test it and see. You may need to run a bit in your tanks filter, too, to keep
the pH stable in the tank itself. Depends on your carbonate hardness.
When it's time for maintenance, you then only need to siphon your gravel into a
bucket, and hook a piece of Eheim hose onto your powerhead to refill the tank
from your Rubbermaid bin.
Piece 'o cake! :)
One last thing...do you use an undergravel filter, and if so, how often to you
clean it? You need to siphon your gravel (with or without an undergravel) quite
regularly, since the detritus that builds up can lead to a low pH in the tank
itself. All debris decomposes over time, and in the course of this becomes
acidic, hence, a lower pH. Low pH problems in the tank water generally always
means a good cleaning of the substrate is required. -Gwen>>
Low pH Levels
Hello Crew
<Randy>
I have been reading your articles with interest in an attempt to understand why
I cannot maintain a neutral pH in my fresh water aquarium.
To be quite honest, there is so much information here I find it a little
overwhelming, and also confusing.
<Mmm, I frequently encourage folks to read the articles of a topic first... then
the Related FAQs until they gain an understanding of facts, underlying
principles... but it dawns on me that the accumulation, presentation of so much
information, opinions may be disconcerting>
I realize that this question must have come up dozens if not hundreds of times,
but have found very few articles that match my problem.
I have a 100 gallon freshwater setup that has been established for many years. I
run an undergravel filter
<Ahh, a source of enhanced reductive (acidic) activity...>
with four powerheads, and a below the tank Eheim 2228.
I do 50% water changes twice a month, with a gravel
<A calcareous natural gravel I hope>
cleaning, but find that the water in my aquarium is constantly too low in pH
despite the fact that my tap water is very high in pH...off the scale in fact.
<But of what alkalinity? That is, how much alkaline reserve? Water can be of
nominally high pH, but not be well-buffered...>
I use Seachem's neutral pH, but it seems to raise the pH for only a short while,
usually only one or two days before it begins to rapidly drop off again.
At one time I had some natural driftwood in the tank, but realized that this
might be contributing to my problem,
<Easily so>
and eventually took it out.
The tank is planted with artificial plants, and currently houses only Severums.
I have six green and three gold, ranging in size from two to four inches.
<How nice... and this species is tolerant, indeed appreciates soft, acidic water
conditions>
The fish seem to tolerate the low pH, but it seems obvious that they are not
that happy. When the pH is closer to neutral, the fish are much more active.
When the pH begins to drop, they tend to hide, and swim very little.
<Yikes, good observations... most all life does not "like" sudden or drastic pH
changes>
It makes me nervous to be constantly adjusting the pH artificially, and in
addition, I can never seem to maintain a constant value, which can't be good for
the inhabitants.
It seems that most articles on your site deal with the opposite problem...people
trying to lower their pH. I did read one article where you recommended the
addition of some crushed coral to the gravel.
<Yes, one approach... please see below>
I understand that pH is related to many other things, and to be honest I find it
all quite confusing.
My question is...isn't there a good way to raise my pH and keep it up near
neutral without having to constantly add conditioners and buffers to the water?
<Yes, a few approaches>
I would ask why my pH is always low, but I understand that there are many
possible reasons, and would settle for finding a cure rather than understanding
the mechanics involved.
Any suggestions on how to raise my pH levels and keep them up without having to
add lots of chemicals would be greatly appreciated.
Randy
<Your pH is low very likely simply due to a lack of bicarbonate, carbonate...
content... If this were my system, I would develop a habit of using a designated
bucket, plastic trash can... adding a teaspoon of simple Baking Soda (Sodium
bicarbonate) per five gallons and letting it mix, heat it... for next time (I do
weekly water changes on my cichlid tanks). Additionally, you might look into
carbonaceous "natural" gravel, perhaps some stone/rock decor that will bolster
your alkaline reserve, maybe add some "marble chips" to your canister filter...
but not crushed coral to the tank. Do read about the concept of alkalinity, its
relation to pH (one is a measure of "resistance" to change, the other a "point"
on a scale...). You are close to a complete understanding here, and an operant
solution to your vacillating pH trouble. Bob Fenner>
Re: Low pH Levels
Hi Bob
Thanks for the quick reply to my question.
My tap water runs between 5-6 dKH, my aquarium water is near that, testing
between 4-5 dKH.
<Mmm, a bit low... recommended that it be 10 to 12 dKH or 3.5 to 4.5 mEq/liter
or 175 to 225 ppm...>
I understand that gravel is a source for acidic activity, but I do clean it
regularly with my water changes,
<Mmm, the biological activity that results in acidification occurs whether the
gravel is cleaned to a large degree>
I use the Anaconda water siphon kit to accomplish this since I am dealing with
rather large amounts of water.
<Good idea>
I have heard of aquariums with no substrate at all...do you recommend this in
order to reduce the acidic activity?
<Not in general... there are set-ups, reasons for some designs to do away with
substrate/s, but the vast majority of aquarium systems are bettered by having
them>
As for the gravel currently in use, I have no idea as to its calcium content. As
with all gravels I have seen at the local fish stores, it is merely labeled
Mexican beach sand (gravel) or some other non descriptive label that doesn't
give me a very good insight as to its actual chemical makeup.
<Can be tested relatively easy... most simply with a bit of distilled or good RO
water adding a bit of gravel, checking the resultant pH, alkalinity in a day or
two.>
This gravel is of varying sizes and colors and looks rather good in the
aquarium, which was my primary reason for choosing it. If you can recommend a
particular type/brand, or perhaps an online site that has a more complete
description of its products, I would be sincerely thankful now that you have
given me a clue as to what I should be shopping for.
<At this point, I would add the more alkaline crushed material to your canister,
add the baking soda to your change water... leave the gravel as is>
As for the decor of the tank. I would love to add some rock(s) to the tank, not
only for decor, but the fish also seem to appreciate having someplace to
"hangout".
<You are correct here>
Would it be possible to give me some tips here on what kind/type of rock(s)
I should consider adding.
<Again, the simplest assay is mentioned above>
Once again, it has been my experience that these things are displayed at the
local fish store, but are seldom labeled as to their type...limestone, marble,
or whatever.
<You might even "collect your own", or check a local garden, rock and block
supply outlet...>
If you know of an online site where I could shop for these things, it would be
most helpful to me. Locally there are only a couple of fish stores, and they are
somewhat small with a limited selection of materials.
<Dr.s Foster & Smith have about the best selection of aquarium supplies
outright... seem to be fair priced, consumer-oriented>
One other thing...I currently only clean my Eheim canister when the flow begins
to bog down...maybe every eight weeks or so. Would it be helpful to clean it
more often?
<Mmm, yes... about once a month... a good idea to incorporate their Grob Flocken
or such, or two "pads" that you can switch out just the outer, dirtier one, move
the older into the "number one" position... to preserve nitrification>
I read somewhere that flow should be your guide on this, but would be interested
in your thoughts.
<Better to not wait for diminished flow>
I would like to thank you once again for your expert advise, and taking the time
to share your knowledge with those of us with a somewhat...umm...lesser
understanding.
Randy
<Glad to share, be of service. Bob Fenner>
Weird water chemistry
Hi,
<Hello there>
A couple of weeks ago I wrote in about some persistent pH issues. I had been
unable to keep my pH below 7.5 even with repeated treatments of acid buffer over
several weeks. At the time I had thought the problem was due to alkalines in my
gravel, which I had confirmed by testing a sample of gravel in a jar (with a
second sample of plain old water as a control) and by testing the gravel with
vinegar.
<Good>
Since then I have purchased a larger tank and am using a new
substrate--Fluorobase (sp?). My water is pH 8.2 out of the tap, and the
Fluorobase seems to have stabilized the pH at 6.6 ~without~ the need for RO or
any acid buffer treatments! I've only had this tank running for a week now, but
the Fluorobase really does seem like absolutely miraculous stuff for those of us
with highly buffered tap water.
<Likely has a good deal of laterite content>
The transition from old tank (high pH) to new tank (low pH) revealed another
factor in the pH change. I removed all the plants from the old tank to ensure
there was no pH variation due to CO2. I also removed all of the gravel, which
should have removed the alkaline source and allowed me to slowly bring down the
pH until it matched the new tank-- or so I thought. What actually happened was
that the pH ~kept rising again~. I'd add some water from the new tank, or a few
drops of acid buffer, and I'd observe a small drop in pH as expected. But, when
I'd test again an hour later, the pH would be exactly where it started!
Ultimately I had to push the pH change much faster to overcome this effect.
Fortunately everyone seems to have survived.
<Dangerous... I recommend the use of an alkalinity test kit... treating new
water OUTSIDE the system... like in a dedicated plastic can... ahead of use by a
few days>
I have since done some tests using the old tank, which is an Eclipse 3g. First,
I thoroughly rinsed the tank. I removed the filter media but left the pump
running. I filled it with dechlorinated tap water (pH 8.2) and added enough acid
buffer to bring the pH down to 6.6. 12 hours later, the pH was up to 7.5. I
added more acid to bring the pH to 6.6 again, and sure enough, 12 hours later,
we're back at 7.5. Meanwhile, a control sample (water in a jug) remained at
exactly 6.6 the whole time.
<Okay>
There is nothing in this tank besides tap water, dechlorinator, and acid buffer.
So, it seems that the water circulation itself must be causing the pH to keep
rising to 7.5! Speculations: (a) the acid buffer is evaporating, (b) the acid
buffer is reacting with dissolved oxygen and losing its acid properties, or (c)
oxygenation is affecting the pH through some other mechanism-- something else in
the tap water. So, I shut off the filter, and 12 hours later the pH had dropped
to about 7.0. This seems to definitively rule out (a), and point to (b) or (c)
as the culprit.
<B likely>
Has anyone ever heard of this phenomenon or care to hazard any guesses as to the
chemistry of this? I am using Seachem Liquid Acid Buffer. All I know is that it
is a non-phosphate buffer.
Thanks, Dave
<Oxygenation is driving the carbon dioxide from the water... it's leaving is
allowing the pH to rise... again... you are almost "there" in understanding the
relationship between pH, alkalinity/acidity and what you're doing... Read a bit
more and you will know.
http://www.wetwebmedia.com/FWSubWebIndex/fwph,alk.htm Bob Fenner>
Re: Weird water chemistry, take tres, David gets very close
Hi Bob,
<Dave>
Ok, so the "acid buffer" is reacting with bi/carbonates (KH) to produce carbonic
acid plus insoluble carbonates, i.e. Ca(HCO3)2
--> H2CO3 + CO3=
and then CO3= + ???. Carbonic acid then dissociates, H2CO3
--> CO2 + H2O. The CO2
is subsequently removed via circulation, allowing more H2CO3
to dissociate, so pH eventually rises again.
<A good model, explanation>
This would also be resulting in increased GH, and this is indeed what I observe:
<Yes>
Tap water: KH 60, GH 65, pH 8.2
Test tank w/ 2 doses of "acid buffer" w/ circulation: KH 25, GH 70, pH 7.5 But I
also have:
Display tank w/ Flora Base substrate: KH ~5, GH 80, pH 6.5 Seems like the Flora
Base (I believe this contains volcanic ash) is doing a very good job (too good,
really) in holding down pH, and it is eating up all my KH. I need to raise KH to
minimize pH fluctuations, right?
<Possibly... not be disingenuous, or overly-slippery here... it "depends" on a
few other factors... For instance, will you have a "large" bioload of plants?
These can/will aid you (and themselves) in ameliorating pH, KH and GH changes...
types of foods added, amount of fish, invertebrate livestock will add their
reductive influences (production of acidic wastes, carbon dioxide)... and
regular maintenance... it may be that changing part of the water out on a...
weekly basis? may be fine for keeping KH about right... Understand that the
matter that makes up the KH is not necessarily irrevocably gone... but may be
only weakly, temporarily bound up in your fancy substrate... this is what
happens VERY often in "the real world"... with the hardness coming back into
solution under certain conditions (particularly drops in pH)>
So what is the best way to do this-- in a stable, consistent way? I would
like to achieve a pH of 6.8 with a decent amount of hardness-- this is a new
tank w/only a couple of fish, so I haven't even begun to see any biological
acids appear yet. Will adding crushed corals or seashells (in a bag in the
filter) do the trick?
Thanks, Dave
<I wish all aquarists had your good, inquisitive mind... The "best" way at this
point is to proceed with actual stocking... and observe, test what actually
ensues with the weeks going by... and then, if necessary, in addition to regular
water changes, you might add calcium chloride to increase GH without elevating
pH... Please see here re:
http://www.thekrib.com/Plants/CO2/ Bob Fenner>
Re: Weird water chemistry
Bob,
<Dave>
> [...] Seems like the Flora Base (I believe this contains volcanic ash) is
doing a very good job (too good, really) in holding down pH, and it > is eating
up all my KH. I need to raise KH to minimize pH fluctuations, right?
> <Possibly... not be disingenuous, or overly-slippery here... it "depends" on a
few other factors [...] Understand that the matter that makes up the KH is not
necessarily irrevocably gone... but may be only weakly, temporarily bound up in
your fancy substrate... this is what happens VERY often in "the real world"...
with the hardness coming back into solution under certain conditions
> (particularly drops in pH)>
Hm. Now that raises the concept of "buffering" to a higher, hence juicier,
order of complexity. However, I talked to a tech at the company that
distributes the stuff, and he assures me that the KH is indeed gone, not
bound. A little experimentation is in order here...
<<Could be and sounds like it>>
> So what is the best way to [raise KH]-- in a stable, consistent way? [...]
> <[...] you might add calcium chloride to increase GH without elevating pH
[...]>
I do want to add KH, and raise pH, so that I can begin injecting CO2. But,
since my fancy substrate vaporizes KH, I need a way to do this slowly and
constantly, as opposed to adding pinches of baking soda or CaCl or what not.
<<These are the safest methods...>>
I recall reading somewhere that CaCO3 and MgCO3 are more soluble in acid water
(i.e. something like CaCO3 + H3O+ => Ca++ + HCO3- + H2O)
<<Calcium more so than Magnesium carbonate...>>
so wouldn't adding a small amount of limestone to the tank/filter therefore not
only raise the KH and pH (which is desirable here) but also to buffer the system
against drops in pH?
<<Yes...>>
My continued thanks for your guidance...
-Dave
<Do experiment here... there are a few "formats" of calcium carbonate...
limestone, marble, aragonite... powdered, aggregate... Bob Fenner>
Re: Weird water chemistry
Any recommendations as to which CaCO3 supply would be best given my
environment (ready solubility in mildly acidic environment, small tank,
heavily planted, desiring enough buffering to permit CO2 injection)-- viz.
limestone, marble, aragonite? Crushed coral?
<Yes... I would use a Dacron bag to hold a given (weigh it) mass of Aragonitic
sand of a given grade (3-4mm or greater diameter) and place this in your water
flow path. Not too soluble (low enough Ksp,
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2004-27,GGLD:en&q=solubility+product+constant
) Bob Fenner>
Re: Weird water chemistry
Thanks!
<Welcome... I look forward to our further chatting... there IS a great deal that
could/can be discussed re petfishing and chemistry... but not much that REALLY
is of practical consideration... relative to all the other fields the hobby
entails! Bob Fenner>
Re: Weird water chemistry
Same here, Bob. I am a tinkerer at heart, project manager by trade... have
yet to see a better example of a "dependency-driven resource management system"
than an aquarium.
<Ha!>
I must admit that I do take perverse pleasure in contemplating the complexities
of water chemistry (pain/pleasure being another complex buffered system) but
your point is well taken.
<Ah, good>
So, on another topic-- livestock selection for a specific niche. I have a 12g
cubical tank, more-or-less Dutch-style, back 1/3 forested up to the top of the
water column, medium-height plants front-left and (hopefully) a Glossostigma bed
front-right. Population is currently 1 Betta, who lurks around the bottom when
he's not coming up for air or gearing up for an attempted leap into the sump,
and a small school of H. Rasboras who more or less stick to the large
front-right open area, plenty of room for their shenanigans there. I may also
need a SAE or flag for algae control, though I've been warned about flag/Betta
combo.
<Can become irksome "riders"...>
I am looking for a species that will prefer the mid/upper planted areas, ideally
small (<1") schooling fish (I think I can support 4-5 more if they are really
tiny). I am not fond of tetras in general. Do you have any suggestions?
<Some of the smaller Danios, livebearers like Endler's, Hatchetfishes if you
have a cover (your allusion to the Betta leaping out), even other labyrinth
fishes like the smaller gouramis of the genera Colisa and Trichogaster come to
mind. Bob Fenner>
|
|
