PH level for Malawi Cichlid tank

Hi

I'm trying to set PH to 8.0 - 8.5 as Malawi tank requires,
I was using JBL PH-PLUS to set PH level
and API Proper PH 8.2 to set a buffer (KH)

Now it seems I did reach suitable PH level +- 8.2
But KH seems gone way higher than has to be up to/between 15d-20d

Question is how to stabilize KH and reduce it to/between 6d-10d
Without affecting the PH level ?

My system timed-out whilst doing a reply before.
So, I'll make this brief (as I have to go home soon).

I'm not totally familiar with those off-the-shelf products you mention, but I do have a concern for Malawi water:

Malawi is a Class I lake, which means that in comparison to other rift valley lakes its conductivity is relatively low (around 200 microsiemens, compared to the high conductivity of Tanganyika...a Class II lake).

If more and more electrolytes are added to compensate for pH and hardness, then there is a risk of raising the conductivity way too high for Malawi fish.

So, maybe it would be worthwhile seeing if you can get hold of a conductivity meter whilst adjusting chemistry anymore.

On the chemistry bit, Malawi water is not as complex as tanganyikan water...and they are profoundly, and in principle, very different (and I'm not talking about pH or hardness differences).

Levels of Calcium and Magnesium will affect hardness. In Malawi, the relative mass-concentration of calcium is much greater than magnesium; the reverse is so in tanganyika.
Levels of carbonate/bicarbonate will affect pH (and the type of hardness).

Sodum bicarb will change pH; calcium bicarb will change pH and Hardness; magnesium sulphate (often added in the form of magnesium sulphate heptahydrate) will tend to affect (increase) hardness. All will affect conductivity.
But, I'm always a bit suspicious about test kits for Hardness as they may also measure ions that do not specifically cause hardness.

You may need to start again by diluting your system down slowly and re-adjusting the amount of pH adjusters. With weak acids or bases used in pH adjusters, it is not just the amount added but the ratio of what is added is important.
Do the adjustments with a conductivity meter at hand.
You still need to get a good buffered system irrespective of the actual pH measured.

Ian

Thanks Ian

Very helpful


but what pH adjusters would u recommend ?
and what for buffering it ?
Unfortunately I have no access to Calcium, Magnesium, carbonate/bicarbonate or any kind of acid
So I'm forced to use some ready to go products, and they are so much in the market difficult to choose.

I was recently looking to Kent products "Kent Marine African Chichlid Starter Kit"
any experience with them ?
are they ok?

ok may sound basic but works well for me, just use coral gravel / rock in a filter and this should buffer it perfectly, used by me and some of my friends with no problems and lots of breeding going on, i feel too many people try to get things too perfect and in the process damage their stock, just my opinion, no offence ment

Yes that sound good, and easy way

But as far i know coral gravel buffers not only ph

if let say for some reason NO2/NO3 goes crazy
it will buffers it as well

There are methods to reduce temporary hardness...eg sodium carbonate (bath crystals).
But it also affects pH, and will increase conductivity.

I no longer keep malawi's, but would generally have used a mix of coral gravel and silicates in a substrate mix. Then would use sodium bicarbonate to give a bit of additional buffering (the calcium bicarbonate from reactions within the coral gravel will also act as a buffer)

But, as we know, care needs to be taken when messing with water chemistry.

Maybe the special off-the-shelf malawi salts work well....I'm not sure as I have not analysed them. Maybe I should have a goo at what is in them.

But, in your case, I would suggest starting again and gradually raise pH and measure the hardness as you do it using the product you've used already.
I wouldn't attempt to lower the hardness in the body of water you already. It can be done, but Malawi fish may suffer if the dissolved electrolytes is too high.

Alexus wrote:

Yes that sound good, and easy way

But as far i know coral gravel buffers not only ph

if let say for some reason NO2/NO3 goes crazy
it will buffers it as well

Tell me more about this reported NO2/NO3 buffering.....I would suspect that that is not correct in itself, but maybe a symptom of general unbalanced water chemistry.

The carbonate buffering from coral gravel would actually buffer the system to resist a pH crash when nitrous and nitric acid are produced by the nitrosfying and nitrifying bacteria.

But, as with all of this water chemistry stuff, there are pitfalls: a slightly alkaline pH may favour growth of ammonia oxidisers (nitrosofying bacteria) and nitrite oxidisers (nitrifying bacteria), but ammonia is free ammonia and thus more toxic in alkaline waters.
Hence, the problem of a non-mature Malawi tank if the old bacteria are not established.

Another item, Magnesium sulphate heptahydrate (Epsom salts) is often used to increase hardness……but I would tend to be sparse with its use in Malawi water, even though it may be better be suited for Tanganyikan water (Tanganyikan water is a somewhat magnesium-type water, and a lot more complex water chemistry)

Ian

thanks ian. well written reply and good info there.

just to add to ians informative post.
lake tanganyika water contains high levels of magnesium, potasium and sodium, and lower levels of calcium and trace elements such as iodine. while malawi is mainly calcium with lower levels of the others such as magnesium etc. victoria is fairly similar to malawi.
the most important feature of tanganyika is the very oxygen rich water quality and stable high ph. low oxygen levels (usually caused by too high temperatures and high disolved carbon dioxide levels) must be avoided
so the most important factors in keeping healthy tangs ime are highish (above 7.5) stable ph, strong filtration and aeration and temperature never exceeding 80f. (i aim for about 75f). hardness or lack of does not appear to be a big factor. (i aim for fairly moderate hardness which is easier to maintain than extreme levels)
higher temperature and too low ph are the main cause of death and disease in tanganyikan cichlids imo.

it is possible to have high general hardness and low ph and vice versa, and levels of kh or temporary hardness are important to buffer ph.
from personal experience ph and temperature are the factors that need to be correct and reasonably stable and the priority is to keep the water oxygen rich. other parameters although important are not critical.

derek wrote:

just to add to ians informative post.
lake tanganyika water contains high levels of magnesium, potasium and sodium, and lower levels of calcium and trace elements such as iodine. while malawi is mainly calcium with lower levels of the others such as magnesium etc. victoria is fairly similar to malawi.
the most important feature of tanganyika is the very oxygen rich water quality and stable high ph. low oxygen levels (usually caused by too high temperatures and high disolved carbon dioxide levels) must be avoided
so the most important factors in keeping healthy tangs ime are highish (above 7.5) stable ph, strong filtration and aeration and temperature never exceeding 80f. (i aim for about 75f). hardness or lack of does not appear to be a big factor. (i aim for fairly moderate hardness which is easier to maintain than extreme levels)
higher temperature and too low ph are the main cause of death and disease in tanganyikan cichlids imo.

Good additional notes there, Derek.

To emulate Tanganyikan and waters fully is not an easy job. Often Malawi and tanganyikan waters are lumped in as 'being the same' when, in fact, the basic principles of the chemistry are quite different.
Hardness is a bit of a debatable topic.....'what type of hardness?' is really the question: true 'hardness?' or 'hardness as measured by a Test Kit?' (they can be two different things).

Silicates????? not an easy job to emulate the silicate levels. But, to what extent does that really matter (in long-term captivity)?

Some methods to 'soften' water work to soften water alright.....but could be pretty detrimental to fish as they are intended to do one thing: 'soften water' (and usually only for the purpose of washing or fulling Wool in a woolen mill!!).

It may even be the case that some natural waters 'seem' to have a high hardness, but technically may be relatively soft.

Sodium bicarbonate (sodium hydrogen carbonate) may sometimes give a high reading of 'carbonate hardness' in a test kit....yet it is not really a 'water hardener'.

Stability, as Derek says, is the key word...especially of pH.

On the topic of pH.......one can add some much of 'Q' and so much of 'Y' to make a pH of 'X'; and if you add a little bit more of 'Q' and a little more of 'Y' then you can still end up with a pH of 'X'. etc etc

The danger is that whilst concentrating upon pH, the electrolyte levels are rising.
In a Tang Tank, the conductivity can be quite high (as it is a Class II lake), but Malawi water should not have such a high conductivity (I think I quoted the value above somewhere).

Aaagh, I could write about this all night..but some parts are in danger of leading into heavy chemistry... ..but I'm heading home now.

ian

i enjoyed reading and agree fully with ians comments on this very complicated topic, and for those reasons and others i always reccommend keeping it simple and concentrating on the key points of ph. temp. and oxygen (the lifegiver).
over the years i have dabbled in water chemistry with mixed results and much frustration and have noted how fish reacted to different water values. i have also met and spoken to professionals in the fish world and the one thing they all seem to agree on is to keep conditions fairly stable and the fish are healthy.
it is almost impossible to maintain very high ph above 8 without constant monitoring and additions of salt etc which can then affect other values, and as ian says even the devices we use for measuring can give misleading results. far better to aim for a lower level of 7.5 to 7.8 and keep it fairly constant.

Good tread folks.
Informative treads like these seem to be few and far between these days. Unfortunately.

I have no experience keeping Malawi's or Tanganyikan's.

How do you prepare the water for both? Or do you just let the water chemistry alter in the tank using different substrate, rocks etc.?

Yes i'm just trying to extract more info from you guys

hi darren
as the source water in my area is soft, i prepare malawi tanks with one tablespoon marine salt and one teaspoon breadsoda per 100 litres and then with water changes just add smaller amounts pro rata. with tanganyikans i would double this dosage.
the substrate and rocks will work to buffer the ph and keep the hardness up. tufarock (limestone) is very good with malawis and most tangs but not with tropheus as they might graze it with bad results. if tufa is put into very soft water it disolves somewhat whereas in hard water it dos'nt.
correct temperature is also very important for these fish for several reasons such as biological filtration and oxygen levels. i am convinced that tangs and deep water malawis (careleus, electra) do very badly when kept at high temp for any lenght of time.
tangs such as paracyprichromis. leptosoma jumbo, benthichromis, gnatachromis, doubosi, frontosa are all deep water species and all require deep tanks with moderate temp and high oxygen.
the deeper living fish also are less agressive than the species found in shallower depths.

Excellent thread, really enjoy reading it even though I don't keep hardwater cichlids. I have question coming but I am still formulating it


Just a comment on temp and oxygen levels from Derek's post, but just a reminder to readers that the higher the temp the lower the oxygen level, so additional aeration is required.


Daragh

Great thread.

I think it's also important to note that the fish you're keeping most likely never lived in one of the rift lakes so emulating their "natural habitat" is a bit of a moot point.

I keep Malawis. I'm lucky enough to live in the hard water area. I generally add bicarbonate of soda to keep the pH in the 7.6 to 8.0 region. I think it's important to have realtively stable pH/hardness rather than one that matches your fishes "natural habitat".

daragh. absolutely. thats why i always prefer lower temps to increase oxygen to the benefit of fish and filter bacteria.
it is reckoned by some that temps above 85f will even kill off tangs due to increased metabolic rate and reduced oxygen.

i agree ken, stability and easily atainable water values is the key to keeping our fish healthy and happy.

Nooo! Don't you hate wen you get logged off for taking to long doing a post.
I wont be typing all that again.

KenS wrote:

Great thread.

I think it's also important to note that the fish you're keeping most likely never lived in one of the rift lakes so emulating their "natural habitat" is a bit of a moot point.

I keep Malawis. I'm lucky enough to live in the hard water area. I generally add bicarbonate of soda to keep the pH in the 7.6 to 8.0 region. I think it's important to have realtively stable pH/hardness rather than one that matches your fishes "natural habitat".

I guess that many fish nowadays have never seen a rift lake, but that was not always the case.

The earlier days of Malawi/tang keeping was basically ‘wild-caught’ stuff…..and deep water fish were a great challenge.

There were lots of reports on water chemistry…..some correct; some likely to be correct; and some simply made-up from thin air (guesswork….often based upon mis-interpretation of correct chemical data).

Tinkering around with water chemistry can have devastating effects; a water system is made-up of much more than the components that can be readily measured by an aquarium test kit.

So, yep, trying to fully emulate any natural freshwater system is probably going to fall way short of the mark.

Ian

hello

can I use potassium hydroxide with minimal dosage to raise PH up ?

isn't it harmful ?

Cheers

Alexus wrote:

hello

can I use potassium hydroxide with minimal dosage to raise PH up ?

isn't it harmful ?

Cheers

Potassium or sodium hydroxides are strong bases. They fully dissociate, and therefore, in themselves, do not buffer…….but they may alter or displace the buffer capacity of existing weak acids and weak bases.

You could add potassium hydroxide to raise pH……but it is a risky job.

You’d need to add it to a large body of aquarium water OUTSIDE of the aquarium environment first.
Then add that back to the tank very slowly to avoid sudden jumps in pH.

The amount that is needed to obtain a given rise in pH depends upon the existing buffering capacity of the water and upon what the buffers are.

I’d really need to draw a diagram to show the effect….to show the real problem.

If water has little buffering capacity already, then adding potassium hydroxide should NOT be used to alter aquarium pH. The water will be dangerously unstable.

Potassium hydroxide should only be added where the water will continue to act as a buffer…..ie be at a state where the water will resist pH changes upon addition of small amounts of acid or base.

Potassium hydroxide will increase the overall conductivity, and increase potassium levels. Remember that potassium as a weight-by-weight comparison is about 1.7 times heavier than sodium, but Malawi water has about 3 times the mass of sodium as it does potassium.
Hence, you could be taking the sodium/potassium balance to a risky level (and sodium/potassium balances are very important).

But, yes…..it can be done to raise to pH…..you just need to be careful; I personally wouldn’t recommend it without knowing how much buffer you have in your water though. Ie you should be adding a buffer before the potassium hydroxide.

SAFETY FIRST: And, potassium hydroxide (as with sodium hydroxide) needs to be handled with care by yourself………addition to water is exothermic.
If you add neat potassium hydroxide then the temperature can come close to boiling; never add water to a concentrated potassium hydroxide solution…..always add the potassium hydroxide solution to water.

I’ll be at the Fish show this weekend, you could always come and hunt me down.

Ian