I set up a new rio 120 tank 5 weeks ago and went through the fishless cycle, last week the reading were Ammonia 0, Nitrites 0 and Nitrates 10.

At the beginning of the week an electrician turned up to put in more electrical sockets which involved drilling and knocking holes in the wall, i had already syphoned out half the water and put into containers to enable the tank to be moved for better access to the electrician but no cloth was placed over the fish tank and a fair amount of dust got in. I syphoned that water out, cleaned up the tank, refilled the tank with the water i had previously placed in containers and topped up the rest of the tank with tap water (with dechlorinator).

I assumed that the tank would need to go through a cycle again due to the quantity of tap water introduced so i checked the readings and they are Ammonia and Nitrites 0 and Nitrates 10. My question is, does this mean my tank is 'still cycled' or does it mean it hasn't started??

Sorry for the long winded post but i don't want to put any fish in until i'm sure

Many thanks in advance

Jane

are you adding ammonia to see if there is bacteria in the filter? or just testing the new water?

I have just tested the new and old combined water

hi, one way of checking is to put in ammonia to 6ppm (see aquarium calculator at head of this page) and if it drops to zero in 12 hours while nitrIte remains at zero too then tank has remained cycled.

If you have had no fish in since the tank was cycled and have not been adding ammonia then your benificial bacteria will have died anyway.

The nitrate reading may already be present in your tap water and not the end product of a cycle.

Please state you exact history from start to now or try my first suggestion

Hi, The source of ammonia i used from the start was a small handful of fish food in a stocking end and waited for it to rot. Where i live it is very very difficult to find ammonia in a bottle and used this method when i set up my first tank 3 yrs ago. The rotting fish food worked well and water tests were monitered as they should be.

When the tank was cycled and readings for ammonia, nitrite were 0 and nitrates were 10 i put 4 danio's in the tank, they were fine and i kept them in the biggest container with the filter and heater when the electricians came a week later.

Due to the amount of dust that was in the new tank i put the danio's in my other tank (in another room), emptied the tank of water, sucked up any debris from the sand, added the water from the other containers and topped up with fresh water. The filter (fluval 3+) has never been switched off (apart from 1/2 hour when workers had to switch electricity off) and it has been running ever since.

I have been putting a few flakes of fish food in the tank since Monday as advised by LFS to keep feeding the filter. Should i class it as uncycled and start again with the fish food in a stocking end again? I have left the danio's in the other tank for now until i know the situation.

Many thanks in advance

Jane

Hi, further to my post above, i managed to track down some pure ammonia at the weekend so on Saturday i added enough to take the reading to 5. Today i tested and ammonia is at 0 and nitrates are off the scale.
Do i add ammonia again to take the reading up again?

many thanks in advance

Jane

What are nitrItes at? If ammonia is 0 after 12 hours, you're at least in the second half of the cycle, but you want to make sure nitrite is also 0 after 12 hours. If both go to 0, then you're cycled. NitrAte is normal, it'll usually be off the chart with a fishless cycle, just do a large (90-100%) water change to get it out.

This post has been edited by Corleone: Jul 14 2008, 05:54 PM

hi, thanks for reply,

Nitrite test only goes up to 5ppm and the water test was darker than 5. When i tested yesterday (24 hrs after adding ammonia to 5ppm) I only did nitrite test as had run out of ammonia test kit and the nitrates were showing at 0.25ppm, today bought new ammonia test kit and its at 0 and nitrites have risen. Do i wait another day before doing anything?

Thanks in advance

Jane

nitrites at 5??? isnt this a lot?

Yep, continue to add ammonia as you have been every 24 hours, eventually nitrite will drop.

Ok, many thanks...

Jane

Hi, update now, i added ammonia again on 14th as suggested and yesterday readings showed 0 ammonia and nitrates also at 0. Added ammonia again and have this afternoon and both ammonia and nitrates at 0, does this mean the tank is now cycled and is ok to add fish?

I am away on holiday in 4 weeks for a fortnight and would ideally like to transfer my fish from my other tank to this new one so my sis who is house sitting whilst i'm away doesnt have to deal with 2 tanks.
The only fish i have in my old tank are 3 cory's, 3 black widow tetra's, 2 neon tetra's, 4 danios and a loach.

My question is...How soon can i transfer the fish and which ones first and how long inbetween until all are in. Or is it best to continue adding ammonia to new tank and deal with the fish transfer when i return.

Sorry for all the questions ..
Many thanks in advance

Jane