Tank Cycling

[bighammerfan]

Hi. My tank is currently cycling and i have yet to decide on which fish to buy. Is there a specific ph/nitrate/nitrite level i need to achieve or is it different for different fish?

Thanks Alan

 

[loachman]

Hi. My tank is currently cycling and i have yet to decide on which fish to buy. Is there a specific ph/nitrate/nitrite level i need to achieve or is it different for different fish?

Thanks Alan

For most fish, the pH isn't important as long as it is around 6-8 and relatively stable. Most South American and SE Asian fish like pH on the lower end, and most African fish like pH on the higher end, as a general rule. Most aquarium fish are adaptable within that range.

NitrAte shoot for under 20-40 ppm as that will ensure you are doing adequate water changes to maintain other chemicals in low concentration, although nitrate under 200 ppm is not toxic.

NitrIte should be 0. It is harmful in any measurable concentration.

 

[doresy]

as is ammonia!

 

[waterdrop]

Hi Alan,

I see from your thread in Tropical Discussion that you've talked with the members about cycling. Since you are still deciding on fish, it sounds like the cycle you decided on is a fishless cycle, right?

Part of the hands-on learning in doing a fishless cycle is finding out how important zero ammonia and zero nitrite(NO2) are to a tank and also some feel for the lesser player of nitrate(NO3) which gets taken out of your tank during your weekly water change after you get fish. These, especially the ammonia and nitrite(NO2) are the critical players for beginners to learn about.

Measurement of free protons (aka hydrogen ions, aka H+) via the pH scale, is less critical, as loachman has outlined above. During fishless cycling, the pH test is quite useful from the middle phase onward because both steps in moving ammonia to nitrite and nitrite to nitrate will release significant numbers of H+ ions, making the tank more acid and driving the pH measurement downward. Depending on the "buffering" (the availability of ions with a countering negative charge) of the water in your tank, this acid buildup will either be resisted (keeping the pH from going down) or will take over (causing the pH to quickly drop) and creating an environment that can stop the beneficial bacteria from growing. So posting up, and logging, your pH measurements is important during fishless cycling.

So, how about pH once you get fish? The most important rule for beginners to learn is that stability of pH is more important than that actual number that pH sits at in your tank (for the most part.) Trying to "move" pH (to "create" an environment that you think you need for a particular species) is usually a bad (or difficult, if you must do it) thing and ideally is to be avoided. Combine this with what loachman was saying above. Most fish these days are not "wild-caught" and often come from a different pH than what the write-ups will say about their wild preferences... in general.

Having said all that, its not a bad idea (if you can handle this sciency stuff, lol) to get a feel for the pH and KH of the water you've been given by your water authority from the tap (or from your well or whatever.) Thinking of this as your base can help. Once you understand it you can predict that certain species will be easier for you and others might be harder or impossible. ....on the other hand, if getting this technical is -not- fun for you, then just learning the beginner basics about staying pH-stable and running your fish choices by the members here should keep you out of trouble and get you started. Its all in what's fun for you!

~~waterdrop~~