Cycling tank using a prawn

[Willba200]

HI all, your probably thinking "oh not another stupid question". Here goes, I am in week two of my cycle and all readings were at zero, so I decided to put in a couple of raw prawns! My questions are: how often do I need to check my tank readings?
When nitrates etc start to spike do I take prawns out?
Also do I need to do a water change straight away? Thank you

 

[TheTodd]

I test daily, but that's just me being impatient and obsessive. You take your ammonia source out when ammonia and nitrites hit zero and your nitrates are elevated. Then do your big water change to get those nitrates out of the tank and lowered.

What were you doing for ammonia the first two weeks?

 

[Willba200]

Thanks for your reply, live rock and live sand . I was told to leave it for a month. Every test I did showed nil! So like your good self I too am a little impatient and wanted to speed things up

 

[TheTodd]

The cycle needs an ammonia source. Live rock and/or live sand help speed the process up, as they already have some of the beneficial bacteria. When things are all set, you should be able to dose your tank with pure ammonia (up to 3 ppm) and it will drop down to zero within 24 hours. It is usually all set when your ammonia and nitrites go to zero and you are left with just nitrate. Nitrates get removed by partial water changes (and some macro algaes use it to grow, which can pull some out).

 

[Willba200]

So am I correct in putting the prawn in to help speed the cycle?

 

[TheTodd]

Yes. Without it breaking down and providing ammonia, there will be no cycle. It all starts with ammonia.

 

[Willba200]

Hi guys, just tested water. Shrimp been in for 24hrs. Nitrate is between 0-5.0
Nitrite is 0
Ammonia is 0.50
So I'm guessing things are happening? I take it nitrite and nitrate will start to rise also? Do I leave the shrimps? I'm guessing yes.

 

[Willba200]

Also my water has gone a little cloudy

 

[Willba200]

Hi again , day three and these are my readings
Ammonia is 0.25
Nitrite is 0
Nitrate is is. 0
Any thoughts as to cycle?

 

[mistersprinkles]

Hi again , day three and these are my readings
Ammonia is 0.25
Nitrite is 0
Nitrate is is. 0
Any thoughts as to cycle?

It's going to take more than a few days to cycle. Do you have live sand or live rock in the tank?

 

[Willba200]

Yes both

 

[Willba200]

The tank has been cycling for 21 days but only 3 with prawns

 

[Willba200]

Lfs told me to leave it for a month! But during this all tests showed nil. That's why prawns are now in.

 

[Willba200]

Ok, ammonia is 0.25 everything else is 0 is it possible it cycled before prawns were added?

 

[mistersprinkles]

The tank has been cycling for 21 days but only 3 with prawns

Without an ammonia source, the tank wouldn't really have been cycling. That's the thing.