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Help understanding ph/adjustment

welshie

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Hi all, I'm having some difficulty understanding ph and was wondering if anyone would be able to lend me some knowledge?

This may go on while as I have lots of questions. So I apologise in advance.

This started about a week ago. Well...I started this about a week ago haha. Basically I've been trying to breed cherry barbs in a breeding tank after watching them spawn in my community tank. I set up a breeding tank using a matured sponge filter and water from the com tank. After 4 attempts (the 4th being last week) and not once having any of the eggs hatch I looked into my parameters and all was fine until I did the high ph test (api master test) it came back purple indicating 8.8ph! I did a test on my com tank and it read between 7.8 and 8.0 which is normal as my tap water is 8.0 ph. How can the new tank be so high? I used the water out of the same tank? The tank was cycled...well it's never shown any ammonia or nitrite on any test.

Next bit.... I've been using tropical aquacid ph minus. I done a few tests in a few buckets of tank water and worked out what I thought was the correct dosage ratio to knock the p.h down 0.2 ph at a time as to not shock the fish 1ml per 2 gallon( tank is fishless at the moment). When I applied this dosage to the 5g breeder and tested it 1 hour after dosage, it took the ph test from purple to orange which indicated it had dropped by 1.4 - 1.6 ph according to the chart. So I left it alone puzzled and confused! Lucky there was no fish. I tested it 24hrs later and the ph had gone back up to about 8.0. This is where I decided to throw the towel in and ask an expert! I dont know if this is supposed to do this? Is this stabalising? How can it fluctuate so much?

Sorry this seems to go on and on I tried to explain my situation and reasons for doing so as throughally as possible.
 

Byron

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Water chemistry is a very complex subject. We have had this same pH issue come up in two or three threads in the past couple of weeks. I will start by explaining the GH/KH/pH connection because this is key to understanding why pH will or won't change. I will cut/paste excerpts from an article I have posted elsewhere, and use separate posts as this is lengthy.

Water hardness is the measure of dissolved mineral salts in the water, a portion of the TDS (total dissolved solids). There are two basic types of hardness of importance to aquarists, termed general hardness (abbreviated GH) and carbonate hardness (abbreviated KH, from the German “karbon” [carbon]). The combined GH and KH is sometimes termed “total hardness,” but this is of less importance because the GH and KH individually impact the water in different ways.

General Hardness is determined primarily by the minerals calcium and magnesium; GH is sometimes referred to as “permanent hardness” because it cannot be removed from water by boiling as can KH. GH is measured in several different units, but in the hobby the most common are parts per million (ppm) and degrees (dH or dGH). One dGH equals 10 milligrams of calcium or magnesium oxide per litre [1], and is equivalent to 17.848 ppm. Multiplying dGH by 17.9 gives ppm, and similarly dividing ppm by 17.9 gives dGH [the same formula works for KH]. The following chart equates the degrees and relative ppm to common terms in the hobby.

0 - 4 dGH 0 - 70 ppm very soft
4 - 8 dGH 70 - 140 ppm soft
8 - 12 dGH 140 - 210 ppm medium hard
12 - 18 dGH 210 - 320 ppm fairly hard
18 - 30 dGH 320 - 530 ppm hard
over 30 dGH over 530 ppm very hard

Fish are directly impacted by GH and TDS; their growth, the transfer of nutrients and waste products through cell membranes, spawning (sperm transfer, egg fertility or hatching), and the proper functioning of internal organs such as the kidneys can all be affected.

Carbonate hardness is the measure of carbonate and bicarbonate ions; carbonates and bicarbonates are the salts of carbonic acid. It is sometimes referred to as Alkalinity [not to be confused with alkaline as in pH, something very different]. Carbonate hardness is also measured most often in either degrees (dKH) or parts per million (ppm), and the same formula to convert dGH to ppm and reverse also works for KH. KH is normally tied to the GH, since carbonate minerals include limestone, dolomite, calcium and calcite. Mollusc shells and coral are primarily calcium. Carbonate hardness is sometimes called “temporary hardness” because it can be removed from water by boiling which precipitates out the carbonates.

KH has some direct impact on fish; but it also “buffers” the pH by binding to additions of acids or bases, keeping the pH stable—or more correctly, preventing it from changing—and the higher the KH, the greater the buffering capacity. A simple way is to think of the buffer as a sponge that soaks up the acid being added; however, at some point it will become saturated, and further additions of the acid can then cause a sudden and very large fluctuation which is usually fatal to the fish. This buffering is why attempts to adjust (lower) the pH of hard water are dangerous and will fail unless the KH is first reduced.

pH stands for pondus hydrogeni, Latin for “potential of hydrogen.” Water is made up of positively-charged hydrogen ions and negatively-charged hydroxyl ions, and pH is the measurement of the ratio of hydrogen and hydroxyl ions in a body of water. Acidic water contains more hydrogen ions, and basic (alkaline) water more hydroxyl ions; neutral water has an equal proportion. The pH is closely linked with the level of carbon dioxide (CO2) because CO2 produces carbonic acid. The hardness also impacts pH, since the carbonates bind to acids as they appear; as mentioned previously, this buffering will prevent or limit changes in pH.

The pH is measured with a scale from 1 to 14 with 7 being neutral. Numbers below 7 indicate acidic water, increasingly more acidic as they lower, while numbers above 7 indicate basic or alkaline water, increasingly as the numbers rise. This scale is logarithmic, meaning that each unit is a ten-fold increase/decrease; so a pH of 5 is ten times more acidic than a pH of 6, and 100 times more acidic than a pH of 7, and a thousand times more acidic than a pH of 8. Fish must never be exposed to sudden pH changes approaching one unit, as this is very stressful and may kill some species.

The impact of pH on fish is significant; water constantly enters the fish via osmosis through the cells, and the pH of the water can shift the pH of the fish’s blood if they are different. The fish must therefore regulate its internal pH accordingly, and this takes energy. Fish do this regularly in nature in response to changes in its environment, but these are usually minimal. Some fish species have a wider range of tolerance than others, for reasons that are not certain.[2] Fish that are wild caught show intolerance for hardness and pH levels that are not close to their origins. Maintaining a species in water that is reasonably close to its natural habitat is usually advisable.
 

Byron

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[This is the second post following the above.]

Adjusting water hardness and/or pH should only be done by natural means, never with chemicals and preparations because these will often be “blocked” by the initial KH and may have or lead to other effects that can be highly detrimental to fish and bacteria. Water should always be prepared outside the aquarium and then used to gradually replace the aquarium water over a period of time to avoid shock to the fish.

Hard water can be made softer by diluting it; Reverse Osmosis (RO) water, distilled water, and rainwater can be used. Water will soften in proportion to the dilution; mixing hard tap water half and half with one of the afore-mentioned waters will result in water that is half the original hardness. A caution on home water softeners: many of these work by replacing the calcium [Ca] and magnesium [Mg] ions with sodium (=common salt) [Na] ions. Each Ca and Mg ion is exchanged for two Na ions. Therefore, the end result is water containing twice the ions--or double the total dissolved solids--it previously had, and for soft water fish this is an even worse situation, plus there is the detrimental impact of the sodium (salt).

Soft water can be made harder by using calcareous substances in the filter (preferably) or the substrate. Dolomite is the best, since it is composed of both calcium and magnesium. Crushed coral, marble and limestone also work but need to be in crushed form (gravel, sand) to have more of an effect. If these latter are used, magnesium can be added with Magnesium Sulphate [pure Epsom Salt] at each water change; very little is needed. The amount required can vary depending upon the softness of the original water, but in general, very little calcareous material is required.

Adjusting pH should not be attempted except in conjunction with altering the GH and KH, since these are closely related. Most municipal water supplies will be medium hard to hard with a correspondingly higher pH in the basic range (7-9). It would not normally be necessary to raise this further, but if the tap water range is medium hard with a pH in the 7’s, adding a calcium or magnesium base to increase both the GH and KH will naturally result in a higher pH, as one might do for rift lake cichlids.

The GH and KH will remain steady once adjusted, provided no substances to increase it are present in the aquarium. Once the KH is low, the pH will naturally lower due to the carbonic acid being added to the water from natural biological processes such as fish and plant respiration, bacteria through the breakdown of organics such as fish waste, uneaten food, plant matter, etc. Regular partial water changes using either similarly-prepared water or even tap water [in smaller amounts] should not overly impact the hardness and pH if the tank is biologically stable.
 

Byron

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The foregoing two posts will explain why the pH is not lowering. Never attempt this with fish in the tank as it can be deadly. And never use chemicals to adjust pH because it rarely if ever works.

If you have further questions after the above, feel free to post and I'll do my best. I am not a chemist, but one has to understand these basics or the fish will bee the losers.
 
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welshie

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Screenshot_20190602-012955_Samsung Internet.jpg
this is my tap water from the water company website.
 
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welshie

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Thank you for your reply. I think I understand now why the ph level dropped and rised again as it was being 'buffered' by my water. I'm still struggling to get my head around all the gh/kh stuff.
 

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The GH and KH are high, meaning you have hard water. The pH is not going to lower significantly at all, unless you reduce the GH and KH, and this can only be done safely by diluting the source (tap) water with "pure" water. This is possible but takes effort. Water changes must use this prepared water.

Hard water fish species will do well in this water as it is. Livebearers, rift lake cichlids, some rainbowfish, and some others are hard water species.
 
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welshie

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My tap water also comes out about 8 ph. The water round here is ground sourced and we have a few limestone quarries around so I should think that's one of the causes to the water being hard. In the summer when its gets really hot we have to run the tap for 20 seconds because otherwise the water comes out white!
 

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My tap water also comes out about 8 ph. The water round here is ground sourced and we have a few limestone quarries around so I should think that's one of the causes to the water being hard. In the summer when its gets really hot we have to run the tap for 20 seconds because otherwise the water comes out white!
Yes, that would make sense.

By the way, when testing tap water for pH, you need to ensure any CO2 is out-gassed first as this can result in an iinaccurate test result. Just let a glass of tap water sit for 24 hours then test pH. Or very briskly agitating the tap water for several minutes can out-gas the CO2. If there is enough CO2 (this can enter the water anywhere along the route through the pipes) it will lower the pH temporarily, but after 24 hours CO2 dissipates from water and the pH will then show more accurately. This is not necessary with tank water, just tap water, and only with pH tests.
 
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welshie

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The GH and KH are high, meaning you have hard water. The pH is not going to lower significantly at all, unless you reduce the GH and KH, and this can only be done safely by diluting the source (tap) water with "pure" water. This is possible but takes effort. Water changes must use this prepared water.

Hard water fish species will do well in this water as it is. Livebearers, rift lake cichlids, some rainbowfish, and some others are hard water species.
I mainly keep barbs after my gourami passed. Cherrys, gold, black ruby and 5 banded. Also have 2 yo-yos. I've just recently obtained 2 apisto cacatuoides which are in there own tank at the moment and I know the water round here isnt good for them. They have bog wood and Indian almond leaves in there and Ive used a peat extract water conditioner but still the p.h is high..
 
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welshie

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Yes, that would make sense.

By the way, when testing tap water for pH, you need to ensure any CO2 is out-gassed first as this can result in an iinaccurate test result. Just let a glass of tap water sit for 24 hours then test pH. Or very briskly agitating the tap water for several minutes can out-gas the CO2. If there is enough CO2 (this can enter the water anywhere along the route through the pipes) it will lower the pH temporarily, but after 24 hours CO2 dissipates from water and the pH will then show more accurately. This is not necessary with tank water, just tap water, and only with pH tests.
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Yes I did that. Not done it for a while as I didnt think the tap water would change much but I know the tank sits about 7.8-8.0.
 

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I mainly keep barbs after my gourami passed. Cherrys, gold, black ruby and 5 banded. Also have 2 yo-yos. I've just recently obtained 2 apisto cacatuoides which are in there own tank at the moment and I know the water round here isnt good for them. They have bog wood and Indian almond leaves in there and Ive used a peat extract water conditioner but still the p.h is high..
The pH will remain high. The GH and KH are strong in your source water and they are going to maintain a stable pH. This is why the pH chemical didn't work, and it is also why organics like peat, dried leaves, wood will not work either (at lowering pH I mean, there is nothing wrong with the organics themselves providing tannins and such). You could at some point have sufficient peat/leaves/wood to impact things, but it would mean an immense volume, and it would give out relatively soon. The only way is to dilute the source water, but unfortunately this is not a one-time operation but one to be done at every water change and that can get involved.

Apistogramma cacatuoides is likely to be tank-raised, not wild caught, so the parameters at the breeder's are more important. This dwarf cichlid often does quite well in hardish water.

Barbs are strictly speaking soft water fish, but they seem better able to manage in harder water, up to a point. They too are likely to be tank-raised, not wild caught, these days, the common species anyway, and that seems to help things. Sometimes a species can manage, some cannot.
 

seangee

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That is hard water. The only way to lower the pH is as @Byron suggests by diluting it. Its pretty similar to my water supply. I was able to bring this down by mixing it 50/50 with RO water in one of my tanks. In the other tank, which has softwater fish I mixed it at a ratio of 1:2.
In my case I had the added complication of very high nitrates in my tap water so I had to filter the tap water before mixing with the RO. This proved quite a hassle as I typically change around 150liters per week - so I went all in and bought an RO unit and use re-mineralised RO all the way. Of course this is still a hassle and can be expensive if your water is metered so you do need to think carefully about whether this is the way you want to go.

Do you have any substrate in the spawning tank? I would not expect the pH to go higher than your tap water of its own accord
 
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welshie

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The pH will remain high. The GH and KH are strong in your source water and they are going to maintain a stable pH. This is why the pH chemical didn't work, and it is also why organics like peat, dried leaves, wood will not work either (at lowering pH I mean, there is nothing wrong with the organics themselves providing tannins and such). You could at some point have sufficient peat/leaves/wood to impact things, but it would mean an immense volume, and it would give out relatively soon. The only way is to dilute the source water, but unfortunately this is not a one-time operation but one to be done at every water change and that can get involved.

Apistogramma cacatuoides is likely to be tank-raised, not wild caught, so the parameters at the breeder's are more important. This dwarf cichlid often does quite well in hardish water.

Barbs are strictly speaking soft water fish, but they seem better able to manage in harder water, up to a point. They too are likely to be tank-raised, not wild caught, these days, the common species anyway, and that seems to help things. Sometimes a species can manage, some cannot.
Cacatuoides should be ok then. Yes I suspect their tank raised as them seem to be doing ok. Cherrys even spawned in the tank. But they also made light work of eating the eggs up Haha. Yes that does seem to be a bit involved.

I have read that a ph change of 0.3 can cause harm or death to fish.. so if I was to go about softening the water with r/o how would much tank water would i change at 8.0 ph a time to prevent a ph shock? Also If this is true and injecting co2 into a tank will lower ph how come the ph change doesn't effect the cherrys barbs in my aquascaped co2 injected tank? Hopefully you can see where my confusion is coming from Haha.
 
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welshie

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That is hard water. The only way to lower the pH is as @Byron suggests by diluting it. Its pretty similar to my water supply. I was able to bring this down by mixing it 50/50 with RO water in one of my tanks. In the other tank, which has softwater fish I mixed it at a ratio of 1:2.
In my case I had the added complication of very high nitrates in my tap water so I had to filter the tap water before mixing with the RO. This proved quite a hassle as I typically change around 150liters per week - so I went all in and bought an RO unit and use re-mineralised RO all the way. Of course this is still a hassle and can be expensive if your water is metered so you do need to think carefully about whether this is the way you want to go.

Do you have any substrate in the spawning tank? I would not expect the pH to go higher than your tap water of its own accord
Yes I have taken a few cups from my community tank to cover the bottom. The bog wood stays in there all the time and the tank is always running even when empty. I know as @Byron said the ph will change over 24hrs as the co2 exchanges with co2 but my comm tank sits at around 8.0 and the water and gravel is from the same tank which is why I didnt understand how the ph could rise to 8.8? The only thing I added to that tank is moss for spawning from the comm tank and when the barbs spawned is used an infusoria culture and liqifry no1 liquid fry food. Surely that isnt raising the ph? And if it is by 0.8 over the space of a few days?
 
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