# how long can fishless cycled tank go without ammonia?



## Hardstuff (Oct 13, 2012)

My Q.T. fishless tank has super high nitrates. I am currently doing water changes to get them down to say 20ppm. I want to bring in some new fish stock for my 10g planted tank which is doing excellent but has nothing in it but 2 cherry shrimps & snails. I was using 100% r/o water with Gh booster & baking soda + ammonia , dosing PO4 to help maintain a good bio population. I do not want to kill my bio system. My LFS said 24-48 with no ammonia is fine. I have my doubts. Right now I am getting 80-100ppm of nitrate, & after 2- 50% water changes today my nitrates are still holding 80+ppms. I plan on doing another 50% water change tonight & reluctantly cut in 20% tap so I dosed prime. When I have dosed (prime) in the passed it screws up ammonia readings & shows less ammonia than present. Thats why I have been cycling with 100% r/o water with booster & trace. I needed more water tonight & my r/o could not keep up with me so I started cutting in the tap with prime. Now I am fully committed for fish right now. Now I will not be able to get proper readings for ammonia. The fish I want to bring in are called Amber Tetras. Can they take say 40-50 ppms of nitrates if I can get the tank that low & will I risk crashing my bio system without food for more than 24 hours. Best ideas appreciated. On a similar note the LFS keeps his fish at Gh 18 , Kh 20. Yep you cant make this stuff up! Should I try and come close to match it or should I compromise & shoot for somewhere in the middle , like Gh 10, KH 5 ??? High Kh would kill my Ph! Best ideas appreciated. Thanks


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## 50089 (Dec 11, 2011)

Ember tetras are very pretty fish, I have some too, you'll enjoy them. Why are you using RO, just b/c of the Prime readings? I haven't found that Prime interferes with ammonia readings at all. RO water is basically distilled water which has zero nutrients for the fish or bacteria so unless you plan on adding some minerals (Kent's RO Rite or Seachem Replenish) I'd start using the tap water. Bacteria can live without ammonia for a decent amount of time; I'd say a week tops before you start losing some bacteria, definitely 1-2 days is fine.


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## msawdey (Apr 6, 2009)

test your water, my guess is that you have nitrates in it.


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## Hardstuff (Oct 13, 2012)

My water does not have detectable NO3 in it. I use a blend of R/O water to cut my high Gh+ I use CO2 & the tap kh is to high as well. I would kill my fish if I used Straight tap. I am setting the Q . t. tank for the pet shop fish , then I will gradually bring it down over the course of a month. Yes prime has thrown ammonia readings off and I am not the only one that has noticed. You better look at your readings because they may not be correct. I have been doing this for awhile now without problems & nice plants. Thanks


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## Diana (Jan 14, 2010)

I would do something close to 100% water change and use new water that matches what the Ember Tetras are currently used to (ask the supplier). Acclimation will be the easiest if GH, KH, pH, TDS are what they are already swimming in. 

Do not dose any ammonia. Nitrifying bacteria is just fine without any ammonia for a few days. 

There will probably be remnants of NO3 in the substrate that will enter the water column pretty fast and help the plants for a few days. Then you can start dosing the fertilizers again.


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## DaTrueDave (Oct 16, 2011)

Instead of adding straight ammonia to maintain your cycled tank, consider adding a pinch of fish food every day instead. This will feed the bacteria in a manner much more suitable for ensuring a complete (and non-toxic) cycle.


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## Hardstuff (Oct 13, 2012)

I would not use flake food since if any parasites are introduced from fish down the road it will give them extra food to feed on. Especially trichadina, & costia.These organisms feed on bacteria & dirty substrates. Then there is planaria which is not a parasite but problematic.The tank in question is doing well now. I would recommend fishless cycling to anyone but would try seedless method. That is going to be my next experiment. Just make sure to have enough Kh & minerals in water as well as PO4. PO4 has been saving my butt a lot lately. I had a hospital tank going with a sick fish in it. Cloudy fungus looking water after meds. The meds trashed my bio filter, so I cleaned the filter & took out the sponge, nothing left in the filter. Then I did a 70% water change , put new sponge in internal filter added some PO4 to help feed the bacteria & the next day No ammonia or nitrite shown on tests & crystal clear water. I have noticed many times after worrying about losing bacteria because of ammonia staying high after cyling, doing a fishless cycle. After adding PO4 the tank bounces back in less than 24 hours!!


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## DaTrueDave (Oct 16, 2011)

Hardstuff said:


> I would not use flake food since if any parasites are introduced from fish down the road it will give them extra food to feed on. Especially trichadina, & costia.These organisms feed on bacteria & dirty substrates.


What do you think you're growing by adding ammonia? You're growing bacteria and starting a life cycle in your tank. Whether you introduce nitrogen in the form of straight ammonia or in the form of fish food is up to you, but you were asking about keeping a tank cycled and adding fish food is an excellent way to keep it cycled.


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