Not sure whats going on?

[ChrisGLA]

Hi Guys,

I am new to this and just starting my first aquarium. (I used to keep fish when i was around 14 years old but i have lost all my knowledge since then). I am hoping someone can shed some light on whats going on with my cycle.

I bought a second hand tank around three weeks ago now and the previous owner switched off and drained the tank the night before i was due to collect. I then set up and switch the tank back on with water in three days after collection.

The tank was then running for seven days (fishless) but i was adding in bacterial growth booster throughout this time. I will mention at this point that i didn't clean the filter prior to re starting. I thought it might have been a good idea to keep the media as is to help the cycle. On the seventh day i also done a 40L water change as the water was very tainted due to the drift would which i have in there (purchased from a fish shop).

On day nine i bought seven rosy tetras and added these into the tank. (i was advised that this will help with the cycle).

On day ten and with the fish only being in the tank one day i done a water test and i got the following results,
pH - 5.0
Ammonia - 1.0 mg/L
Nitrite - 0 ppm
Nitrate 0 ppm.

I have now ran the tank for seven days (16 days in total) with the rosy tetras being in and i done another test with the following results, (I will add that all the fish are doing great and eating very well)
pH - 5.0
Ammonia - 0.5-1.0 mg/L
Nitrite - 0 ppm
Nitrate 0 ppm.

The tank is 155L and the current temperature is 26c.

Correct me if i am wrong but after having the fish in the tank for seven days i thought i would expect to see a rise in nitrates and a decrease in ammonia?

I'm just surprise to see the results being pretty much exactly the same seven says after adding fish. Is there something going on or is there something i am not doing right or is this normal?

Please help a newbie out as i'm still trying to get my head around all of this. Do i carry on as i am doing and i should start to see a difference or should i change or start to do something else?

My end goal is to also have a pair of discus in the tank.

Thank you.

[Second Hand Pat]

Hi Chris, this is normal as it can take 6 weeks to cycle a tank. The best way to cycle a tank for discus is by doing a fishless cycle as you avoid contamination from other fish, plants this way. I would suggest you start in the beginner section with the stickies. Start with the video in this one, long but well worth your time http://forum.simplydiscus.com/showthread.php?122038-Are-you-new-to-discus-WATCH-THIS-VIDEO!.
Pat

[Kyla]

In addition to avoiding contamination, using a fishless cycle allows you to prepare your tank for a much higher bioload.. so there is enough beneficial bacteria (BB) to consume all the ammonia produced by your discus immediately.

The BB only grow to match the amount of "food" (ammonia) being produced, so if u put a school of small fish in the tank to cycle it, the BB will only grow enough to breakdown the ammonia being produced by those small fish. Then later when u add more large discus there won't be enough BB present to break down the higher levels of ammonia produced by the new fish, and the tank will experience another cycle while the BB grow to match the new bioload in the tank - this will stress the discus.

Doing a fishless cycle let's you add lots of ammonia so you have enough BB present for when you add your discus.

[ChrisGLA]

Much appreciated for your replies and knowledge.

Going from what you are saying Second Hand Pat, i'm guessing this is normal within the cycle and its just a case of hanging on and letting it do its thing for a few more weeks? I was advised to add in fish to help the cycle as i am looking to have a community tank with a pair of discus.

Kyla - As above i was advised to add in some fish to help the cycle but i understand what you are saying. Would it be a good idea to keep adding small numbers of fish as the cycle is continuing so that the tank gets fully cycled and the BB continues to grow? What i am now worried about is keeping the seven tetras in the tank on their own and the BB stop growing but what i'm cautious about is adding alot of fish when it is still going through its cycle. What would you advise is the best path to proceed with?

Thanks.

[Ryan925]

Much appreciated for your replies and knowledge.

Going from what you are saying Second Hand Pat, i'm guessing this is normal within the cycle and its just a case of hanging on and letting it do its thing for a few more weeks? I was advised to add in fish to help the cycle as i am looking to have a community tank with a pair of discus.

Kyla - As above i was advised to add in some fish to help the cycle but i understand what you are saying. Would it be a good idea to keep adding small numbers of fish as the cycle is continuing so that the tank gets fully cycled and the BB continues to grow? What i am now worried about is keeping the seven tetras in the tank on their own and the BB stop growing but what i'm cautious about is adding alot of fish when it is still going through its cycle. What would you advise is the best path to proceed with?

Thanks.

The best and safest bet is to sterilize the tank, media and equipment then start a fishless cycle. You will run a large risk of contamination issues from the previous owners fish and your new additions

[Willie]

Unless the tank has had discus previously, I don't see how there would be "discus" pathogens in there. If there were, they couldn't survive in the absence of discus. My recommendation is to let the tank cycle with the dithers.

You didn't mention what kind of filter was in there previously. If it was a canister type, they go anaerobic very quickly when shut off. So you may be re-starting your cycle. You have ammonia, but not nitrate. In a cycled tank, the results would be flipped.

Willie