5 in 1 test Strips

seangee

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What about our tanks that are say 6.8 ph. Then what?
I suspect 6.8 will be quite similar to 7, but will just take longer to cycle. I did see an explanation of the NH3/NH4 ratio on here (possibly @essjay ???) but I confess it was way over my head.

What we do see a lot on here is people with a pH in the range of 6 - 6.5 who don't undertstand the cycle and add fish (as advised by LFS) and then keep adding fish at 2 weekly intervals. Then one morning they wake up to a tank full of dead fish. My explanation for this (may not be correct) is that it takes much longer for the nitrosomonas to establish and there is no loss of fish because NH4 is much less of an issue than NH3. Then eventually the nitrosomonas does establish and starts turning the NH4 into nitrite. So you end up with lots of nitrite very quickly (lots of NH4 to feed on). At this point there is no nitrobacter to turn nitrite into nitrate and fish start dying :confused:
 
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itiwhetu

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I suspect 6.8 will be quite similar to 7, but will just take longer to cycle. I did see an explanation of the NH3/NH4 ratio on here (possibly @essjay ???) but I confess it was way over my head.

What we do see a lot on here is people with a pH in the range of 6 - 6.5 who don't undertstand the cycle and add fish (as advised by LFS) and then keep adding fish at 2 weekly intervals. Then one morning they wake up to a tank full of dead fish. My explanation for this (may not be correct) is that it takes much longer for the nitrosomonas to establish and there is no loss of fish because NH4 is much less of an issue than NH3. Then eventually the nitrosomonas does establish and starts turning the NH4 into nitrite. So you end up with lots of nitrite very quickly (lots of NH4 to feed on). At this point there is no nitrobacter to turn nitrite into nitrate and fish start dying :confused:
Building up a tank to full capacity should take months, life is a slow process, and so is the balance of an aquarium
 

mbsqw1d

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Slightly off topic, but concerning these test strips, grab a pair of scissors and cut them lengthways to double your stock of them;)
 

essjay

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Ammonia (NH3) is a gas which dissolves in water to form ammonium hydroxide. Being a base, it dissociates into its ions, OH- (hydroxide) and NH4+(ammonium). But a small proportion remains as ammonia and this is what harms fish. Virtually all our test kits measure total ammonia - that's ammonia and ammonium combined. But it is possible to work out how much is in the more toxic ammonia form. This ammonia is usually called free ammonia to distinguish it from ammonium.

The amount in each form varies with temperature and pH. Temperature varies little in tropical tanks so the amount of free ammonia in our tropical tanks is dependent mainly on pH.
The equilibrium constant for the equilibrium between free ammonia and ammonium is well known and there are on-line calculators to determine the amount of free ammonia at any given pH (and temperature). This is the one I use
For fresh water, salinity is set to zero and the other parameters entered, and free ammonia is given in "NH3 concentration".

Fish can cope with a free ammonia level of 0.05 ppm for a couple of days; and up to 0.02 ppm for several days. For long term fish health, free ammonia should be well below 0.02 ppm.



@seangee wonders what happens at very low pH where there is virtually no free ammonia. At pH 6.0, even a total ammonia of 8.0 has only 0.0046 ppm free ammonia. But years ago I was taught that ammonium is not non-toxic, just less toxic than free ammonia. This is not mentioned nowadays, and I know of no study to show the effects of high levels of ammonium on fish. If any member does know of such a study, please let us know.



We know that at very low pH, the 'ammonia eating' bacteria do not grow in our tanks but that there is virtually no free ammonia. We also know that at high ammonia levels, a different species of 'ammonia eater' grows which is one reason we need to make sure we do not add too much ammonia for fish cycling.
Question - are the bacteria which grow at high total ammonia levels inhibited by low pH? Or will these 'high ammonia bacteria' grow in our tanks even when pH is very low and keep the ammonium level at a certain point?
 

essjay

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I should have mentioned that when there are live plants in the tank, these take up ammonia and with enough well growing plants there should be no detectable ammonia, total or free.
 

essjay

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Those fish keepers who do not have live plants, for whatever reason, do need to be able to test for ammonia.
In a planted tank (and I mean more than one java fern in a 100 litre tank) the plants will remove any ammonia and they don't turn it into nitrite. But a non-planted or very lightly planted tank relies on the bacteria to keep the fish safe. Even where a tank is mature, the addition of too many new fish at one time can cause an ammonia spike. Something getting into the tank which kills bacteria can cause an ammonia spike.

Fishkeepers with heavily planted tanks probably do not need ammonia testers - or nitrite testers. But those with non-planted or very lightly planted tanks do need them.
 
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