The Nitrogen Cycle

[SnowCichlid]

Yes teh nitrate system is so important.... I hate wehn you find people posting saying that they dont or barly do water changes.....and they wonder why their fish dont live that well

[Luca]

Hi Arden, just one question:
you mentioned that Ammonia is toxic to fish at ph over 7. However earlier on this forum I read that it is better not to play with the ph and leave it at stable tap water range at around 7.6-7.8

So should i aim to keep it at below 7 or do regular w/c's keep the Ammonia levels at bay?

Luca.

[Carol_Roberts]

With a cycled filter and daily water changes you shouldn't have a problem with ammonia in your tank.

[Ardan]

Hi,
Its best not to mess with the ph unless a must. Stability is important.

However if using a med, sometimes water changes are not recommended (using antibiotics for bacteria in early stages of treatment), In this case (Or at least I have done it) ph can be lowered to offset the buildup of ammonia.

Also it is just good to know that at higher ph , ammonia is more toxic. so that if you are dealing with ammonia and have high ph water, that you make more water changes to keep ammonia at 0.

One thing to keep in mind, Nitrite is more toxic if ph is below 7. so once the cycle goes into the 2nd phase (ammonia to nitrite), the lower ph would not be recommended.

One other note, lower ph = slower bacteria growth, this can be useful when treating bacterial infections, however the good bacteria for the filter also grow slower.

hth

[Luca]

Ok thanks very much for the feedback guys. I know it's too soon for me to be thinking about breeding, but when i finally make an attempt are my chances increased with a lowered ph? Carol, you mentioned "Discus need soft water to hatch eggs." The natural water hardness here in New Zealand is 0-1dh, is this too soft?

One other question, you mention daily water changes and of a high percentage....how do you refill all that water at the same temperature? do you just use warm out of the tap of add some boiling water? do you fill buckets or use a hose? just curious.

thanks for all your help, it's great

Luca.

[Carol_Roberts]

I have moderately hard water and a pH of 7.8 in the tank. My well water comes out of hte ground under pressure with a pH of 6.8. I can't do 50% water changes with my tap water as it causes too much pH swing.

I have plastic 50 gallon storage barrels that I fill with water. Each barrel has an aquarium heater and a pump. I use the pump to "age" (circulate, airate, agitate) my water so the pH will match that in the aquariums. I have the heaters set at 84 degrees. I use all my water up during water changes and then refill the barrels for the next day.

Some people with soft water (maybe you?) don't have to worry about pH swing. Their tap water and tank water are pretty much the same pH. Those lucky folks can adjust the temperature of their tap water (add dechlor product to the tank) and fill directly from the tap with either a bucket or a hose.

With your soft water you may need to add buffers or minerals to avoid a pH crash.

[ronrca]

I have a question pertaining to the nitrogen cycle.

I have heard this a couple of times but never really understood it. As the biological cycle consumes ammonia/nitrites producing nitrates, the ph will slowly drop. Why?

[Carol_Roberts]

That biological process consumes carbonates and produces acids . . . .or something like that, lol. Anyway the nitrification process uses some minerals. This is only a problem in soft water. For most of us, water changes add back enough minerals to keep the tank stable.

[xpotato]

Thanks for the information.

I have a question to ask

Currently I am doing fishless cycling for my tank.
I had nitrites off the chat, 10 nitrates, and no ammonia.
Ihave made 10% WC several times but the nitrites is still off the chat.

What should I do to get rid of the nitrites?

[Carol_Roberts]

90% water change. Your tank is showing nitrAte you are cycled.

[ronrca]

I agree with Carol! After you do the 90% water change, test the cycle by adding again 5-8ppm ammonia and seeing how long it takes to 'cycle'. It should not take longer than 2-3 days for ammonia and nitrites to reach 0 again. Now you know that you can fully stock your tank.

Why do I mention this? Well, from my own experiences I would not test the cycle and add fish. What would happen is that ammonia is fine but the nitrites start rising again. This is due to the multiplication rate difference between the two strains of bacteria responsible for ammonia and nitrite. Just a tip!

[Luca]

Hey Carol -
you say your tank water is ph7.8 but your well water is 6.8, does it rise in your storage container??

my ph has been crashing and swinging all over the place due to its 'blankness'. the kh is 2 the dh is 0 ph is 7.8

as a result my fish have got some strange black disease (i'm guessing from the stress of ph swings). the temperature was also fluctuating until i got a large filter up and running (via aqua 750), before that i just had an aqua clear mini on the tank (70gallon).

i think the first thing i should do is get these minerals i need added to my substrate, what do i do?

distressed.

[Carol_Roberts]

The pH rises in my storage barrels as the CO2 is off-gassed by water agitation. I don't know very much about soft water like yours . . . . April has soft water. Why don't you start a new post in the water section. I think there is a receipe there for the minerals needed to stabilize your water.

[delmore]

[quote author=Serpae link=board=2;threadid=934;start=0#msg31011 date=1032479927]
Optimum pH for sustainable biological activitiy (microflora) in the aquarium is stated to lie between pH 6.5 and 8.0...[/quote]

When I fishless cycle my pH jumps from 7.4 -> 8.0+
The ammonia must cause the spike in the pH. Anyone know why this is? I am cycling a 55g bb tank now. Nitrite - 0,nitrate -0, ammonia - about 5ppm, pH around 8.

[Carol_Roberts]

I think ammonia itself raises the pH.