Cycling tank with fish questions!

[Travis32]

Hey everyone, I am knew to this site and really need some input from anyone with experience please! Let me give my tank setup. I have a 75 gallon tropical freshwater tank that I am currently cycling with fish (I know I should have done fishless), the fish are Zebra Danios. Anyway, the cycling has been going on 2 weeks now. For the last 3 days, my ammonia levels have been 0, my Nitrite levels are super high at like 5, and my Nitrate level is at around 20. I am assuming that means I am to the middle stage of cycling, the Nitrite stage? Hopefully that is what those numbers would indicate, please let me know. Also, just for some information, I am using the API freshwater test kit, I keep the tank at 74 degrees, and I have two filters I am currently using (The marineland Emperor 400, and the Marinland Penguin 350). I also am using Prime and Stability. Please give me any advice and let me know if I am headed in the right direction. Thanks everyone!

UPDATE: I keep getting conflicting information on water changes! Some say big water changes daily, some some minor water changes multiple times a day, and some say no water changes while cycling. What is the recommended course of action for water changes during cycling? Especially in my case of very high Nitrites? Thanks

 

[Travis32]

Anyone?

 

[sinibotia]

You just want to keep your nitrites low for your fish. So do water changes however you prefer to keep nitrites around .5 or less. Whether that's a big change, a bunch of small changes, or whatever.

 

[Fel]

Nitrite takes a decent amount of time to go down, during my fishless cycle mine went to 3, then off the charts. I was lazy and since it was fishless didn't do any water changes, just documented 10+ nitrite level and waited it out. It was that way for almost a week then one day it was 5 and the next it was 0 (looking at my log here).

The NOBs (Nitrite oxidizing bacteria) take longer to go through a generation than the AOBs (Ammonia oxidizing bacteria) which is why nitrites tend to stay high longer than ammonia.

Personally I'd do 40-50% water changes, especially in a 75 gallon. The fish are stressed enough, doing a huge water change every day will add to that, where as a 40-50% will be less noticeable to the fish. Make sure your treating the water you put in, if your water contains chloramine your going to add a bit of ammonia.

You have to do a water change though, it in now way harms your cycling and since you have fish in there they constantly produce ammonia anyway which gives something for the bacteria to eat.

Keep in mind if you have any friends that have aquariums you can always get some of their filter material and toss that puppy in your filter to help speed things up.

 

[Sonata]

Are water changes necessary when cycling a tank with no fish in it ?

 

[Fel]

Are water changes necessary when cycling a tank with no fish in it ?

They aren't necessary most of the time. The only time you have to do it is if your cycle stalls due to the bacteria not having any micronutrients they need. This is uncommon and most of time just waiting it out is enough.

They can be convenient when you have a measurement that is off the scale.

The only time you have to do one is at the end before you add fish to remove nitrates (as there should be no ammonia/nitrite)

Sent from my HTC6515LVW using Tapatalk

 

[Brad McLaughlin]

Hey Travis, I think your range of recommendations is due to people assuming what your end result is.

Someone who thinks you want to keep the fish alive and healthy will recommend water changes to get your levels in a safe range. However by doing so your removing those toxins needed to build your biofilter and ultimately just slowing the process.

Someone who assumes you don't plan on keeping the fish as part of your aquarium after would probably tell you to just let it be and it will balance out on its own.

Personally dinos are pretty tough fish and can take the abuse while cycling a tank and that's why many people use them.

Hope this helps and of you can let us know your end objectives so we can advise more properly.

Brad McLaughlin
Tampa Bay Area

 

[missie86]

When mine was cycling and my nitrites were sky high I used the emergency dose of prime every few days along with 20%wc (mine was only a 10g though) and it eventually leveled off after about 1 week.

I solemnly swear that I am upto no good!

 

[nerdelish]

When I was fishless cycling and in my nitrite stage, I ended up changing the water nearly everyday to get a decent nitrite reading because my kit only went up to 5 ppm and my levels were sky high. I was told that overly high nitrite readings can stall a cycle so I opted for frequent water changes.

Someone gave me this link and it helped me out a ton: Fishless Cycling

 

[Sonata]

Very informative. Thanks. It does make me question though. Why add ammonia when the objective is to get rid of it because it is dangerous to the fish ?

 

[nerdelish]

Very informative. Thanks. It does make me question though. Why add ammonia when the objective is to get rid of it because it is dangerous to the fish ?

You add ammonia to build up ammonia eating bacteria in your tank. Ammonia at high levels hurts fish. If you add ammonia to your tank you help grow the bacteria needed to keep your fish healthy and happy.

Fish waste has ammonia in it, so if you don't fishless cycle you will still deal with ammonia but have to worry about very frequent water changes to keep levels down (if you want fish to thrive).