Cycling & pH?

Question

Can someone PLEASE explain cycling to me in very plain terms. I keep hearing about it and I don't know what it is.......Also, I can't seem to get my pH any lower than 7.4 I'd like to see it down around 7.0. I've tried the pH lowering liquid and tablets. Just don't seem to help. Any suggestions? I'll add that we have well water and a water softener. Would this affect it?
TIA

Answer 1

Cycling. I'll give a brief explanation and a link to a really good and easy to follow explanation at the bottom of the page. Cycling refers to the nitrogen cycle that occurs in a tank. Bacteria convert the ammonia that fish make as waste into nitrite and then into nitrate. Each step makes the ammonia safer for the fish by converting it into safer compounds. It takes some time for this to occur in a tank as the bacteria need time and ammonia to grow. It can take 2 months sometimes for every thing to work correctly.

As for pH. I would strongly suggest you NOT try to change it. Unless your tap pH is somewhere over 8.0 most any fish will do just fine. A constant steady high pH is far better on the fish than a pH that bounces up and down all the time because of chemicals. Yes, a water softener will make a significant difference in the pH and lowers it indirectly. Or, more correctly, allows it to move downward, but that's a fine point. To be totally honest, not adjusting your pH will be the smart move.

Here's the link:

http://www.firsttankguide.net/cycle.php

If you still have any questions after reading the link, or any questions about pH etc, please feel free to email me.

MM

Answer 2

Hi Karen,

First, don't worry about the difference betweem the pH of 7.0 and 7.4. Most of use use some sort of colour comparison chart to estimate pH with our pH kit, that itself will give us a slight margin of error. And 0.4 isn't goin impact the fish alot. The MOST important thing here is to keep pH constant and the fish will adapt to the pH. A fluctuating pH will cause more stress to a fish that adapting to a pH slightly off their prefer pH (if there is really one).

Next, Dragonfly's simple version of the nitrogen cycle :).

You know animal poo and pee, and this polute the water. This waste will contains ammonia ( the pungent choking and burning smell that you get at some public toilets from urine). Ammonia is not good for the fish and high ammonia causes the fish immunity system to weaken and disease will strike and the fish gets into trouble. Imagine staying in that toilet, anyone will get sick too :)

But there are natural bacterial in water and air that eats the ammonia. This bacterial (lets call it bacterial A) eats Ammonia and breath in oxygen and they produce a compound call Nitrite (or NO2 as some people who can't spell will write :) ). Nitrite is toxic but not as bad as Ammonia. For EXAMPLE it takes 100ml of ammonia in a tank to make a fish sick, it'll take 300ml of nitrite to do the same thing. But remember a sick fish is still a sick fish so this is not good either.

As nature would have it, there is another bacterial ( Bacterial B ) that eats nitrite. These bacterial breath oxygen and digest the nitriate to become Nitrate (NO3). This compound is still toxic but much much less toxic then the other two. Maybe (for EXAMPLE) it take 1000 ml of this to get the fish sick.

So in a senario where you have 10 fishes that produce 2ml of Ammonia a day, if you don't have Bacterial A in your tank your fish starts to get sick on the 5th day. So thats bad.

Say if you have Bacterial A (enough to eat all the ammonia produce) but no Bacterial B your fish start to get into trouble on the 15th day.

But if you have A and B (enough to eat all the ammonia and nitrite produce) you have got 50 days before your tank is in trouble, so if you change water every 20 days, your fish will never get sick due to nitrate.

SO WHAT IS CYCLING A TANK????

The answer is ......... "The effort of growing Bacterial A and B in your tank.".

When you start a new tank and fill it with clean fresh water, because the water is clean (no ammonia or nitrite) there is very very little bacterial A or B in the water.

Say for example you need 100 bacterial A to eat 2 ml of Ammonia and produce nitrite a day. With 10 fishes in the above example, you need 1000 bacterial to eat all the ammonia produce a day. But in the begining there is only very few (eg. 5 poor bacterial A ) in the clean fresh water, so with the food source (which is your fishes) they will multiply. Maybe you'll have 10 on the second day and 20 on the thrid and 40(3rd), 80(4th), 160(5th), 320(6th), 640(7th), 1280(8th). So you get all the Bacterial you need by the 8th day. :)

Wait a minute? That means on the first 7 day there isn't enough Bacterial A to eat all the ammonia produce daily, so the amount of ammonia must be accumulating.....! Thats why you have to do routine water change during cycling :)

Oh yes, we forgot bacterial B. Hmmmm..... actually bacterial B start getting food on the first day, because there are already 5 bacterial A. But because the amount of nitrite in the first few days are so little, the growth of bacterial B is much slower (or maybe bacterial B has slower grow rate this part I am not very sure) the nitrite in the water starts to accumulate. In the above example of Bacterial A after 8 days all ammonia produce will be convert into nitrite (so ammonia reading is zero) but because the slower growth of bacterial B, nitrite starts accumulating this is call the Nitrite Spike (it may or may not happen). Until the bacterial B multiply to the require amount then Nitrite reading will be zero as any nitrite produce will get eaten completely and turn into nitrate. :)

That will be the end of the cycling process. It when Ammonia reading is zero and nitrite reading is zero and the nitrate reading accumulate over the days. Your tank is now CYCLED!

The above example is a very very simplfied version of whats happening in the cycling process. I hope I given you some idea of whats happening during the process. :) And I hope I have not confuse you more with my good intention :)

The cycling process actually is a very complex process, that involves variables like tempareture, pH, chemical (chlorine), bio-media, initial seeding, concentration ( too high ammonia concentration inhibit bacterial B grow), etc, etc. But who in the right mind wants to know about those :P

Disclaimer :

******* All numbers given above are not accurate, they are used as example only. Bacterial grow rate and time is also not accurate. Actual not a single number given in the examples above are accurate. *******

Answer 3

The best type of water softener is reverse osmosis. You can buy a big jug at your local water supplier store. I have a reverse osmosis unit and use it in all my aquariums and it helps reach that certain PH level especially if breeding fishes. Use a quarter tank of RO water with tap water. Tap water is hard, so buy adding RO water, it will help soften the water and reduce stress in your fish.