Understanding toxicity impacts between pH level and Ammonia.
How does pH affect the toxicity of ammonia?
Table 1 - the Nitrification and Ammonification process.
The Ammonia reading you get from test kits is actually the sum of Total Ammonia - which is made up of Ammonia NH3 + Ammonium NH4.
At low levels of pH (lower than 6.0), ammonification occurs. Remember, pH is an inverse count of Hydrogen (H). At low pH, you have more Hydrogen. At high pH, you have less. At these low levels of pH (high acidity), the ammonia NH3 'absorbs' (for lack of a better word), an extra Hydrogen ion -> becoming NH4 or ammonium.
The reason Ammonium is less toxic to fish and shrimp is because NH4 with that added Hydrogen H ion is now less permeable to the gills of fish & shrimp. NH4 is also excreted across the gills via a carrier mediated process in exchange for sodium Na+.
Ammonia toxicity is also influenced by temperature:
The lower the temperature the less toxic it becomes. Or to put it another way - NH3 toxicity increases with temperature and pH.
Percent NH3 of total ammonia Temp pH 6.5 pH 7.0 pH 7.5 pH 8.0 pH 8.5 20C / 68F 0.13 0.40 1.24 8.82 11.2
25C / 77F 0.18 0.57 1.77 5.38 15.3
28C / 82F 0.22 0.70 2.17 6.56 18.2
30C / 86F 0.26 0.80 2.48 7.46 20.3
Table 2. Un-ionized NH3 as a percent of total ammonia (by temperature and pH).
Assuming a temp of 28C and a pH of 7.0 - if 5ppm of ammonia is present this results in only .03 ppm ammonia.
However, in a Tanganyikan Cichlids tank with a pH of 9.0, that has a Total Ammonia of 5 ppm, your ammonia level is 2.06 ppm! This now become toxic for the fish.
But, at a pH of 6.0, and 10 ppm of Total Ammonia, the ammonia is only .007 ppm. Even though we have MORE ammonia.
So be cautious when performing water changes in a low pH tank, as the low pH has an adverse affect on the nitrifying bacteria that converts ammonia to nitrite. Because of the acidity these bacteria populations can drop so low that any change in alkalinity can cause the Total Ammonia reading to rise quickly. While the pH stays low the Total Ammonia reading is nearly all ammonium, but if you do a water change or add an alkalinity buffer to the system, the ammonium can be quickly converted to ammonia, potentially causing ammonia poisoning.
It is good to note here that, as per the very top picture (table1) ... nitrifying bacteria that convert ammonia NH3 to Nitrate (NO3) does NOT convert Ammonium NH4 to a less toxic form. The bacteria isn't present in sufficient amounts in such low pH environments to process it. Ammonium NH4 is ever present in a low pH tank that has living creatures in it. NH4 is in there ready to be converted into NH3 at the first sign of added alkalinity during water changes. Hence, why we always tell you to match water parameters and add it into the tank slowly (drip it in if you can), don't dump in buckets of new water all at once.
So in summary, the combination of low pH (<6) and cool temperatures that the shrimp live in can mean that high ammonia levels are not toxic to them. But be careful !!! Any change in the pH buffer that increases alkalinity will cause the toxic ammonia to immediately convert from NH4 to NH3.
There you go. Hopefully that is a more precise explanation to aid your understanding.
The ideal spot to be is just above 6.1 to 6.5, where bacteria still function, and ammonia is less toxic. Along with the cool temperatures some shrimp (or fish) live in, is the best environment to be in to minimise ammonia poisoning.
I wonder how many times our shrimp die in hot temps, (say due to hot weather ... maybe even a broken heater) not because of the heat, but because our low pH tanks have not enough functioning bacteria to cope with the sudden change in toxic NH3 ammonia due to the rise in temps??? Food for thought.
I have had a 20 gallon RCS tank for 3 years now. I have moss balls and some JAVA moss, drift wood, and mineral rocks.
Only RCS in the tank and some soft shell snails I have in there I breed for my fresh water puffer fish in another tank,.
My issue is that the shrimp live 1-2 years and they breed just fine but I never see babies. I see plenty of eggs but never babies. (Well 1 or 2 a month maybe but they disappear)
The adults keep going just fine until they die off of old age or something else.
I keep about 100 shrimp in the tank and have to replenish 50 every 6 months about.
Water Temp I keep about neutral.
PH- 7- 7.2
I use distilled water or sometimes Reverse Osmosis water because our tap water goes through a water softener which puts a LOT of salt in it which makes TDS very high so I try not to use tap water at all.
I feed every 2 days with Azoo or other good food and not much. Its all gone by the time I feed again.
I do add some powder food for the babies and a shrimp bacteria powder (just started that about 6 months ago but has not helped or hurt)
Someone told me due to the distilled water my issue is LOW TDS. So I bought TWO different meters. I tested the distilled water and its about zero which is correct. I then tested my water and its about 700. I do top offs and just did a 20% water change last weekend with distilled water.
So is that the issue? Should I pull out the mineral rocks?
I am thinking tonight to take about 8 gallons of water and drain the tank down about 40% and then fill with the distilled water. I can repeat the process in a week and once I get the TDS under 150 I can add a little shrimp mineral to get it to the 200 range. The reason I am saying that is the TDS could be bad TDS and not the minerals they needs. I ordered some Salty Shrimp Mineral which I heard was good.
Should I just give up?
Hi everyone, I have spent some time searching (unsuccessfully!) for any threads set up to address how to naturally and chemically treat the more important water parameters. Obviously I'm not talking about temp, but the PH, TDS, KH and GH levels are the ones I'm most interested in. Now I'm country based so the only water I've got access to is R/W and bore (perfectly drinkable from the pump itself, no brackishness) which I have used for 4 of my 6 tanks (tropical and a few lower grade cherries). But I want to better hone in the water condition as best I can so any tricks to raise lower the above parameters naturally or if need be chemically. Or if anyone knows/finds a link, anything will be appreciated.
Had put this in the pinned "Shrimps 101" but will try to delete it as it's probably better as a separate post.
Being rural makes water choice difficult and some of the values I've tested are way out, hence why I'm seeking advice.
Hey SKF peoples,
I'm just mixing up my RO water with a combination of GH+ and GH/KH+ to keep tiger shrimps in. And I thought I'd share my experience, I gradually added the minerals and measured pH along the way and I thought I'd share the results.
I note that the pH may change overnight after letting stand but I have been running a pump in the water to mix it well and aerate it so I doubt there will actually be any measurable shift.
As you can see by the results, the GH/KH+ pushed up the pH a LOT! Does anyone else have this experience? I have achieved my desired water parameters in terms of ppm and GH/KH however the pH is unreal.. and this is not the first time this has happened to me either. However t is the first time I have taken the effort to document the fact.
I'm planning on experimenting with adding a very shallow layer of the cal aqua labs black earth premium and monitoring the pH over the course of days.. expecting it to slowly drop...
Any input is 100% welcome!
love n peace
PS the initial drop in pH after adding the first lot of GH+ I understand can be explained (as I have read elsewhere) that when attempting to measure the pH of RO water using a pH meter the device can not accurately produce any result due to the lack of ions/conductivity in the water.
27/05/2016 EC meter HM TDS-3 pH meter pH APIkit KH GH At time of water mixing EC0 ppm0 fresh RO 6.6 after adding 50ppm GH+ 6.3 after adding 30ppm GH/KH 7 after adding 25ppm GH/KH 7.5 after adding 45ppm GH/KH EC300 8.3 after adding 17ppm GH/KH EC333 ppm175 8.3 7.8 3 8
I'm hoping to get some advice and opinions on managing pH for a tank with cherries and bee shrimps.
My pH is measuring around 5.4 and I'm concerned it may continue to drop over time to unacceptable levels even for bee shrimps. Currently there is only CRS in the tank but I want to add some neos soon.
Firstly some background detail - I have a tank with a modest amount of cal aqua labs black earth premium as per the manufacturer's advice. I use RO/DI water (I changed cartridge recently and TDS of RO is zero) with SS GH+. I keep up with regular WC and the TDS is about 140ppm at last check. The tank is heavily planted, has quite a few pieces of driftwood here and there and also some catappa/IAL. There is oodles and oodles of filtration including canister and air driven sponges, and the stocking rate is low-medium. There is some benibachi fulvic grains in the canister (although these fulvic grains are roughly 6 months old and should be close to expiring now; however I will still remove these fulvic grains when I get around to doing some maintenance on the canister however). The shrimp are quite happy and new ones are regularly getting berried.
Anyway, so aside from removing the fulvic grains and possibly removing the indian almond leaf, and maybe some of the larger driftwood which may help to prevent the gradual acidification that is going on. I am wondering if anyone has experience using small amounts of aragonite or similar to help buffer the tanks. If anyone has any other suggestion or opinion it will be greatly appreciated. I don't fancy that cherry shrimps will breed very well in pH 5.4 or less and I really do want to keep some different coloured shrimps in this setup!
I will be most grateful for any input :-)
love n peace
-edit- I should add that it's true that as a last resort if it really comes to it then I could remove some of the substrate but I don't want to pollute the water in this way if I can avoid it..