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Acceptable Range of PH fluctuations & other general Newbie questions & discussion

5K views 49 replies 6 participants last post by  Elyssa 
#1 · (Edited)
Another newbie question. I'll be getting my CO2 going this morning and plan on monitoring the PH. My KH in the tank comes in at 107.4PPM (6dkh). PH is about 7.6 or so.

What is the acceptable range of fluctuations as to not stress the fish. I'll be testing the PH right before I turn the lights on this morning. I have to hook up the reactor and plan on running the CO2 a half hour to hour before lights come on in the future.

I'm running 2 54W T5HO with option of 2 more bulbs. So will be figuring the lighting out as well.

I just want to know how often I should be taking PH readings throughout the day and when I should just stop the flow of CO2 and for how long.

What are the best practices?

Thanks.
 
#3 ·
There might be some unwanted side effects if the pH drops too much but not directly on fish. AFAIK fish don't care about pH but the side effects can affect them. The nitrifying bacteria slow their activity in acidic water.

Have read at this

pH

The optimum pH range for Nitrosomonas is between 7.8-8.0.

The optimum pH range for Nitrobacter is between 7.3-7.5

Nitrobacter will grow more slowly at the high pH levels typical of marine aquaria and preferred by African Rift Lake Cichlids. Initial high nitrite concentrations may exist. At pH levels below 7.0, Nitrosomonas will grow more slowly and increases in ammonia may become evident. Nitrosomonas growth is inhibited at a pH of 6.5. All nitrification is inhibited if the pH drops to 6.0 or less. Care must be taken to monitor ammonia if the pH begins to drop close to 6.5. At this pH almost all of the ammonia present in the water will be in the mildly toxic, ionized NH3+ state.
 
#6 ·
There might be some unwanted side effects if the pH drops too much but not directly on fish. AFAIK fish don't care about pH but the side effects can affect them. The nitrifying bacteria slow their activity in acidic water.

Have read at this
ah yes but we have plants that help control that
and truly, there are other bacteria that can grow that process ammonia at a slower rate, if this wasn't the case the dirted world we know of outside of planted tanks would have much more ammonia than what is present.
there are always different species where bacteria is concerned. but yes the species listed do function best at those rates. having lots of bio media allows more of the same to be present

my tap water is 7.8 ph, and tank water is 6.5
i change 80% weekly with no ill effects on fish. my rainbowfish are spawning even, and are clearly happy (even more so now they have a bigger home) :)
 
#4 ·
I was confused about the issue from reading here and there.

Am I right in thinking the Ph would lower a bit and then raise back up and since it's more of a gradual up and down, the fish are not affected? It's more PH shock when it bounces from one point to another quickly?

I'm not to worried about the PH dropping to affect the bacteria within the span that the CO2 would be running. My water is not soft.

The whole notion of PH controller was throwing me off, as well.

With the oxygen level, is there away to know how much you have or is it more observe the fish for CO2 poisoning.

I just want to cover my bases before running this. I will be turning it off an hour before lights out.

Thanks.
 
#11 ·
Having the spare equipment here I've placed electronic pH controllers on low light NPT systems just to see what happens with pH during a 24hr period. Lighting alone can shift tested pH by a full degree on lightly buffered tanks (2dKH). Monitoring what the pH reading was in the morning before the photoperiod and again late in the afternoon I recorded a full point shift in value. The only difference was lights on or lights off (more or less CO2). Shifts in the GH, KH, TDS, mineral content, changes in osmotic pressure that's what causes our critters issues not pH changes per say.
The pH value is a product of carbonate buffers and CO2 content in the water for this conversation. Acidic or alkaline yes but testing pH as it relates to tank water and your question on CO2 injection it really isn't anything to worry about.
Am I right in thinking the Ph would lower a bit and then raise back up and since it's more of a gradual up and down, the fish are not affected? It's more PH shock when it bounces from one point to another quickly?
Experiences here are as long as the temperature is matched I can routinely swap fish between injected tanks with 5.9/6.2pH and the 7.4/7.6pH low techs.
Temps the same, the TDS is very close and fish don't seem to care is why I support the position that CO2 induced swings don't matter.

When people say a fish requires a low pH I automatically read that as soft water.
 
#5 ·
i use 100% RO with 0kh and 2-3Gh, PH is 6<, with co2 its even less. i have yet to see any fish being killed by PH sudden change because i do 60-70% water changes during the day once a week, never killed anything with co2 or water changes, unless i gas the fish. however sudden change in Kh could kill them, this is the main reason i prefer not messing with KH with baking soda or chemicals.
 
#7 ·
@happi

Please expand on the kH effect. It's the first time I read about kH being a killer of fish. Quite the contrary when we talk about CO2 poisoning. Adding baking soda will increase kH and lower CO2 levels as that gas will prevent oxygen to bind to hemoglobin. CO2 binds faster thus depriving the fish of the needed oxygen.

@thread starter

I bounced the pH multiple times and didn't experience any deaths. I also read multiple times about this pH shock only to find it is a myth. CO2 and TDS are better killers than the dreaded pH swing.

@HD Blazingwolf

Acidic pH inhibits enzyme activity and even breaks them down. There's no bacteria that can do well without enzymes, even plants are affected by this. A pH lower than 6 is not good for just about anything as the water will be highly unstable chemically wise.

Of course, corrections are welcome!
 
#21 ·
I also read multiple times about this pH shock only to find it is a myth.
Really?
Can you cite sources for this 'myth'?

On the other hand..
Fish Physiology, Fish Toxicology, and Fisheries Management: ... - Page 168

Tropical Fishlopaedia: A Complete Guide to Fish Care - Page 218

Fundamentals of Aquacultural Engineering - Page 26

Pond Aquaculture Water Quality Management - Page 105

The Diversity of Fishes: Biology, Evolution, and Ecology - Page 646

pH Change. Effects on Morbidity and Mortality for Gambusia holbrook, Winkler at al;1979

The Progressive fish culturist - Volume 54 - Page 232

Aquarium fish magazine - Volume 12, Issues 6-12 - Page 42

http://www.skepticalaquarist.com/ph

It seems trendy to treat science is 'Myth'
 
#9 ·
If temperature, kh, and gh are the same but the ph is 1.0 off this is a much safer fish addition than ph the same and kh and or gh being different.
Put simply.
And daniel. Ill try to dig up the article on neem oil, its effects on nitrogen bacteria reduction, and ph efficiency.
Basically a study was done on its effect as a pesticide that would not harm the nitrogen cycle. At ph above 7 things were awesome. Closer to 6 things slowed down but around 5 picked up again.
And neem oil had different effects as well.
 
#10 ·
Not quite the article i was looking for but a brief quote applies here

Because there are only a few species of nitrifying bacteria, nitrification is much more sensitive to environmental conditions than are most other N transformations, which are carried out by a more diverse group of microorganisms. All of the nitrifiers are obligate aerobes, which means that they require atmospheric O 2 so nitrification is especially sensitive to soil moisture content and does not occur in waterlogged soils. The rate of nitrification increases with soil temperature up to about 35°C (95°F); below 5°C (40°F) very little NO 3 -is formed. Soil pH is also important. Below a pH of 6.0, nitrification is inhibited by acidity, and the process virtually ceases at a pH of 4.5 to 5.0. Under alkaline conditions, production of NO 3 -is markedly enhanced. The optimum pH is normally between 7.0 and 8.0, but NO 3 -may be formed at a pH of 9.0 or even higher.
True nitrification slows down but is still possible until the 5.0 ph range

Whole study here
http://frec.ifca.com/1994/report10/
Pretty easy google search on that one
 
#12 ·
To complement wkndracer's explanation, the fish and other living creatures acclimation process is done so that they have time to adjust their osmoregulation to the water's osmotic pressure in your tank.

It's related to TDS which can be *very poorly* approximated from the water hardness (gH). Usually, fish raised in hard water will need a long time (3-4 hours) to adjust to soft water. Death comes almost instantaneous if you drop in fish accustomed to hard water in soft water. But this is unrelated to the pH.
 
#13 ·
wkndracer,
Thanks, I like to keep track of the parameters and realize the KH/Carbon and PH relation. I'm new to the CO2 and understand that the CO2 is going to alter the PH. The woman whose fish and equipment I have, told me she only ran the CO2 for two hours because the PH went from 7.4 to 7.2 and that is where my concern came from.

So, my own water is like 7.6 or a bit more, I was just wondering if I was monitoring the PH every hour, if there was any point I should become concerned. I start at 7.6 before lights come on and 12 hours later if I'm at 6.6 (I'm using random number), I shouldn't have to worry?

I'm so new to all this and trying to wrap my brains around the details now. With the plants using the o2 at night, I have a fluval 304 running and was thinking at night, I should increase the flow for more oxygen and then turn it down in the am when the co2 comes on. It my mind this makes sense, is my logic faulty?

Thanks. Just don't want to stress the fish!
 
#14 ·
wkndracer,
Thanks, I like to keep track of the parameters and realize the KH/Carbon and PH relation. I'm new to the CO2 and understand that the CO2 is going to alter the PH. The woman whose fish and equipment I have, told me she only ran the CO2 for two hours because the PH went from 7.4 to 7.2 and that is where my concern came from.

So, my own water is like 7.6 or a bit more, I was just wondering if I was monitoring the PH every hour, if there was any point I should become concerned. I start at 7.6 before lights come on and 12 hours later if I'm at 6.6 (I'm using random number), I shouldn't have to worry?

I'm so new to all this and trying to wrap my brains around the details now. With the plants using the o2 at night, I have a fluval 304 running and was thinking at night, I should increase the flow for more oxygen and then turn it down in the am when the co2 comes on. It my mind this makes sense, is my logic faulty?

Thanks. Just don't want to stress the fish!
just keep the flow high, have good surface aitation to promote proper gas exchange.

plain and simple. ph changes due to co2 injection are harmless to fish
a safe ph drop for most beginners is a 1.0 ph drop.
for instance from 7.6 to 6.6 like you said

but turn it off at night, this allows bacteria to become more efficient for a good portion of the day.
 
#15 ·
HD BlazingWolf,
Thank you for clarifying and being straight to the point.

With the flow, this is another thing that I've seen so much contradiction on. I thought when you were injecting co2, that running air stones and having a lot of surface agitation was not a good thing and wasteful. If you weren't injecting co2 then it was a good thing because of the gaseous exchange.

I am planning on turning off at night, why would anybody want to run the co2 at night anyways? That just doesn't make sense, unless you didn't have any fish in the tank, perhaps?

Thanks again, big sigh of relief!
 
#16 ·
HD BlazingWolf,
Thank you for clarifying and being straight to the point.

With the flow, this is another thing that I've seen so much contradiction on. I thought when you were injecting co2, that running air stones and having a lot of surface agitation was not a good thing and wasteful. If you weren't injecting co2 then it was a good thing because of the gaseous exchange.

I am planning on turning off at night, why would anybody want to run the co2 at night anyways? That just doesn't make sense, unless you didn't have any fish in the tank, perhaps?

Thanks again, big sigh of relief!
air stones do waste it, BADLY. BUT having good surface agition prevents lots of problems in the future, as well as makes it harder to suffocate your fish with co2

some people run it at night for consistency, and ease of use
 
#17 ·
I think I would rather flip it on and off at this point in time. I'll probably get it hooked up to a timer when I figure out how to set them.

I will keep the flow up and not worry about it. I didn't even think of the difference but I knew I had to take the sponge filter out.

Is there any other pointers you can give me, so I don't make any common newbie errors. You've helped me a lot these past couple of weeks. I don't want any accidental deaths from my ignorance. I wasn't expecting to be at this point as fast as I got here.

Thanks!
 
#18 ·
Elyssa in most cases we don't need to run air stone at all, if you have timer you can setup your co2 to turn on 2 hours before the lights turn on and 2 hours before lights goes off, plant will use any left behind co2 in this period and there is more O2 by the time lights goes off, you can also increase surface movement from filter outlet, power head etc. but, you don't want them to break the water like waterfall.

based on your KH, you will be adding more co2 to get good levels of co2, you wont notice big swings in PH in your water, you will notice that it can drop by 1 ph during the entire day, which will drop slow during the time co2 is on and it will slowly go back to normal during co2 is off.

if your main concern is PH dropping quickly and killing fish, this hasn't happened in my case yet, i even had German blue rams under these conditions, this fish is very sensitive to these kind of changes, the only time i ever killed any fish was due to overdose of co2. you can also kill them if you raise your KH from 0 to 2ppm in one dose, i have tried raising the KH from 0 to 0.5ppm in one dose and did not notice any issue.

good luck with your tank, keep in mind dissolving the co2 is the hardest part in this hobby, everything else is very easy.
 
#19 ·
Thanks Happi,
I have a lot to learn and understand ahead of me. I do want to understand exactly why I'm doing what I'm doing and what is causing the success or failures.

I'm thinking I might want to get up another 55g w/o any fish and experiment a bit more than I can on this current tank. I don't want to mess up and make my tank toxic to the fish.

Today, I finally felt comfortable to get the CO2 up and running. I can already observe that it made the plants very happy.

Is there a standard way to measure your CO2 levels? Tomorrow I will be starting the CO2 in the am, probably about 1 hour before I turn the lights on. I'll put that on a timer when I'm comfortable with the consistent bubble rate and also figure out the reactor (Red Sea-800). I imagine that will need to run 24/7 or it will fill with air if it goes off.

Someday, I'll have more answers than questions but right now I'm doing lots of asking!
 
#20 ·
there are many way to measure co2, there are drop checker, Ph controller, co2/kh chart etc, but best way to measure co2 is by looking at your fish and plants, when adding co2, start slowly with less BPS and increase them little by little till you find the good spot. i never bother to use drop checkers or other methods to measure co2.

fertilizer is also important, make sure you are dosing that too.
 
#22 ·
papwalker,
Thanks for all the references.

happi,
I have to figure out fertilizer, as well. Is there a good quick way to start, just so the plants have what they need. Eventually, I will be doing either PPI or EI and better yet, observation in the end. Is there a good *all in one* product, like the Seachem line? Or something to that end, to tide me over so I can learn more details about individual ferts and deficiencies and all that? Thanks.

Got a glitch with my regulator and didn't stop dispensing last night. So, trying to figure that out.
 
#24 · (Edited)
papwalker,
Thanks for the chart.

I don't know how good this plant diagnosis chart tool is, but you plug in what your looking at and it gives you possible deficiencies. I'm not to that point yet. They also have a few other calculators, as well.

http://www.theaquatools.com/aquarium-diagnoser

Are the Seachem Flourish and Flourish Trace, good products to just start out with, till I start figuring stuff out?
 
#25 ·
Are the Seachem Flourish and Flourish Trace, good products to just start out with, till I start figuring stuff out?
I trust Seachem. They have lots of downloadable documents. They provide scientific explanations and general guidance.

I trust NewLife fish foods for the same reasons.

I trust Hikare.

I trust Eheim.

I trust Colin at Skepticalaquarist for the same reasons.

I don't ever have problems with fish keeping.

hth
cheers
 
#27 ·
danielt,
Thanks for explanation. I have high PH and medium KH values. I never messed with in the tank lowering PH values via chemicals. Out of the tank and experimentation always resulted in getting the PH to drop and then bang, right back up there again. Realizing my water was pretty buffered and best to leave it alone and go with fish that like my tap water. I'm not a chemist and didn't want to take the time to figure out exactly what needed to be to hit the level of stability. I also didn't want to be spending $$ on chemicals to accomplish this and add another worry and maintenance issue.

papwalker, thanks, I have to put in an order to fosters and smith and was wondering if the trace and flourish would cut it for now.

It was all the reading and research I had done on PH and all that when I was first setting up the tank that made me inquire about the shifts when the CO2 is added.

It's good hearing first hand experiences. I feel totally confident now that running the CO2 for 8 hours is not going to kill my fish. I would also think that maybe having a PH controller would serve to really keep it within a smaller range of flux, say between 7.0 and 7.2. But can't afford that right now and might be unnecessary anyways if my PH is only going down a bit. I doubt very much it's going to go down a full point. I didn't take a reading this am on the PH or KH, as I have solenoid issues to figure out.

But tomorrow, I'm going to start charting both numbers. I don't have a clue to KH values and how much they drop off, and what that number should be to keep things stable. How much water changes will keep that number where it should be etc. All I know is after 6 months and regular water changes, it's down approximately 2 degrees from when I started the tank back in August. Just fish only...no plants at all.
 
#29 ·
I would also think that maybe having a PH controller would serve to really keep it within a smaller range of flux, say between 7.0 and 7.2.
Yes, that's an excellent idea! It's just a shame they are expensive.
Start conservatively. This forum is littered with people that admit to killing their fish with CO2. I'd be mortified if I did that.

Also bear in mind people here tend to generalize about fish. Like they are all the same from Arowanas and Bettas to Zambezi Tiger fish.

You'll hear that pH doesn't matter and the next post they'll tell you that fish so and so should be kept at this pH and that temperature.

If you see what I mean.:smile::smile:
 
#30 ·
papwalker,
The skeptical aquarist site is why I decided not to mess with the PH, being comfortable knowing that stable PH was more important then a particular value. I'm just jumping into planted tank and starting research all over again. I'm going to go back to that site and read all I can.

For weeks I had been searching and researching and running across so much conflicting opinions on forums and less on the scientific facts. I'm wise enough to read these answers as opinions and personal experience, unless reliable references are pointed to.

I was just on YouTube the other day researching the Eheim 2026 and setting it up. I ran across a video, where the guy had it set up wrong, filter pad directly on top of grate and to top it off didn't have the little tube connecting the unit to the base. I went nuts, because I had the instructions and could see there was a tube and was missing that piece. I don't rely on anything unless I can make sense of it and understand it.

I have the Milwaukee Regulator and was going nuts trying to get that going correctly, with all the conflicting reports of how to run it. I have it going now but need to figure out why the solenoid isn't clicking when I turn it on, it wouldn't turn off last night.

I respect everybodys opinions and experiences but need the science behind it before I believe anything as truly factual. With aquariums there are so many different parameters and what works for one, isn't going to necessarily work for another, unless all those variables are identical. People that don't realize that, can really run into a lot of heartaches. I totally understand where your coming from.
 
#31 · (Edited)
"See what I mean", yes indeed, figured that out back in August when I first got my aquarium going.

My only concern with a PH controller would be, what is the power went out for 24-48 hours or up to a week or more (it happens where I'm at). I would assume from all this discussion, that since it would be a gradual increase in the PH back to where it would normally reside, it would be okay.

Like I said, I have to really get a feel for the parameters by tracking them. It probably wouldn't be necessary if the daily shift was small. But over a point, I think I'd want to keep it smaller than that.

With the PH and fish. The general notion seems to be everybody will adapt and can adapt. That may be true for most fish. But I see it this way, a city person might not like being stuck out in the woods and a nature lover might go nuts being in a city for extended periods of time. I think it's a matter if the person would thrive if it went totally against their general preference. I feel the same with the fish. They might be existing, but are they thriving?

I would be mortified as well for any deaths due to my ignorance. I actually just adopted 14 fish from a woman and all this equipment for her planted tank came with them. I don't want to make one wrong move and lose my new adoptees. After quarantine from the move they have joined my existing tank, along with their deco and plants. So far, so good.
 
#32 ·
@pap

Why are you being off-topic? I'm sharing my observations from my aquarium. I'm no veterinarian but I read quite a lot about water chemistry and also tested a bit in my aquarium. My pH varies by more than 0.5 day and night without any "shocking deaths".

If you can provide a detailed explanation that someone who's not a veterinarian can understand as to why pH swings kill fish would be great. It would be more helpful to explain instead of quoting texts that need to be sieved before they can be relevant to this discussion or have a swing at me for exchanging my personal views on a subject.
 
#35 ·
@pap

Why are you being off-topic?
I was on topic.
The effects of pH change on fish.

In your post (post #3) you said
"...fish don't care about pH"

Then in your second post (post #7) you said..
..."I also read multiple times about this pH shock only to find it is a myth."

In that context a myth is a perpetuated falsehood, a lie.
As a scientist that's a red flag.


BTW In neither of those posts did you quantify this as a 0.5 pH swing.What I might have said was that it is often the effect of ammonium conversion in an old tank that is mistakenly called 'pH Shock' and referred them to Wetmans site.I really try never to give advice that I can't prove or else I make it clear that it is only my conclusion based on my observations but I'm not sure.If I give bad advise then mea culpa.
We are generally giving advice to people who don't know. That's why they asked the question.Now.
Not all situations and tanks have unbound ammonia. In that case there will be no ammonium conversion. The differential pH effects on their own may cause morbidity due to interaction with the pH of blood in the gills or other effects we haven't identified.
 
#33 ·
danielt,
Thank you for sharing your experiences. I do appreciate it. I can't speak for papwalker, but I think he was being more general than personal. You never stated, follow me and just believe, sister, all will be well...lol....there are others out there that do tend to make statements as that and I think that is more what he was pointing out. As you said, you were just sharing your experiences and research. I do value that as much as I do the scientific papers, especially when the person, such as you can back up that you do have the knowledge behind it and just not doing stuff randomly!
 
#38 ·
papwalker, lol!

HDBlazingwolf, when you put your fish in, did you acclimate them or just go from original tank into the softer water, with no ill effect?

I think another something else could be if they were your fish that you obviously had taken very good care of, and had a strong immune system in the first place, all went well. Taking the fish from a pet store, that just had gotten the shipment in and were stressed in the first place, probably wouldn't fare to well.

I think this is all very interesting to say the least. The fish I just got were in a healthy environment and take well care of. I didn't get all paranoid about the transition because of that and water parameters from her tank to mine being similar.
 
#40 ·
I usually try to acclimate them as much as patience will allow.

The effect of chronic low level stress on the immune system would be better explained by Darkblade48 as it's right up his alley. He being trained as a microbiologist / immunologist.
My main concern would be that fluctuating pH on some species could cause chronic 'stress' and depress the immune system leading to morbidity end eventual death. This could be from malnutrition, opportunistic infection, cellular damage, neoplasia, hyperplasia etc etc. The causative agents might be cortisol and any knock-on effects etc. Death may not occur for months and thus appear to be unrelated to causative events. Or it could be quick if the fish already has an underlying condition.

Sorry to use big words but it's the correct thing to do. I'm not being a smarty, just trying to be factual.
 
#39 ·
OK
Let's go simple.
HCL in solution.

No tds or buffers or whatever.

Now we know that protein, our skin for instance, will be denatured. It will hurt. This can be fast or slow.

From this we might wonder what levels of hydronium or hydrogen ions are required to cause effect on the proteins, binding sites or lipid membranes of cells or alter enzymes, hormones and essential molecular structures.

Thus we can wonder about the cellular nature of fish lamellae (gill structures) and the effect of pH. We may find cells can protect themselves by altering attributes of the membrane. We wonder how far this protection may extend and how quickly it can be accomplished. We may find that lack of evolutionary pressure might leave one organism unable to adapt to pH levels out side of a narrow band whilst others have evolved strategies to deal with this.

Now the effect of proton donation mat not be limited to just gills. It may include olfactory cells, epithelial cells, specialized cells in the gut any of which may come into contact with the solution in question.

I hope this gives you a very general idea on the possible mechanism of how pH may effect organisms other that by osmotic changes alone.

If anyone want's papers or links of actual studies I will attempt to provide them.

Now were well into stuff that I'd not generally discuss outside of a biology or organic chemistry forum.:icon_smil:icon_smil
 
#41 ·
papwalker,

Do you have any links you can dig up pertaining to Biology and Aquatic plants specifically. Terrestrial plants are covered in my Biology text books but they don't address aquatics at all.

Also you got any sites that go into general concepts on aquatic plant fertilization. I did hydroponics a long, long time ago. I figure translation of those principles into a planted tank could be somewhat similar. I don't just want to dose for the sake of dosing if it is not needed. To start I'll do Flourish or something, but down the road, I want to dose exactly what is needed and have more of a scientific approach based on observation.
 
#42 · (Edited)
I could scrounge around. I subscribe to several journals that might have papers on aquatic / amphibious plants that a human could actually read. However plants are not my strong point. I kill them easily.

Start here http://www.skepticalaquarist.com/aquarium-plants

I use the idiot proof varieties in my tanks.:smile::smile:
 
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