Fishless Cyclists...

[bobf]

Hiya,

Having read all the very helpful posts on the fishless cycle I decided to give it a go with my new 30 (UK)gal.

I set the tank up about two weeks ago and tossed in there some sand from an existing mature aquarium.

I dutifully added the ammonia (Boots, household variety!) to get to 6ppm and waited...

After about 4 or 5 days the ammonia levels dropped so I have been adding a bit each day when the level drops to between zero and 0.1 (hard to tell the difference really on my kit). The tank is now 'consuming' about half a capful each day.

The nitrates and nitrites are both 'off the chart' and have been for around 5 or 6 days. The tank has now reached the 'ugly' stage - dayglo green and army green algae forming (as you might expect). So I am now patiently waiting for the 'overnight' Nitrite drop.

My questions are these;

1 Should I continue to feed with more ammonia or stop?

2 Would it help to do a water change?

Cheers!

 

[Bloo]

Do you have lights on in the tank at all during this period ?

 

[bobf]

Yes - the lights are on a timer - would they be better left off?

I'm not unduly concerned about the algae as I plan to keep some Malawis or Tangs in this tank anyway, and gather they are partial to bit of the green stuff! To some extent I can't do a whole lot about keeping this dark anyway as the tank is on a kitchen worktop and the room is pretty well lit, as you would expect.

It's just that I'm a bit impatient about getting the Nitrite down and want to encourage (or at least not delay) that!

 

[Bloo]

I'd leave the light off completely while you are doing your cycle - and not do a water change until it's all done You can then wack the lights on full blast and you'll have some great algae growth again in a few days.

 

[bobf]

I'd leave the light off completely while you are doing your cycle - and not do a water change until it's all done You can then wack the lights on full blast and you'll have some great algae growth again in a few days.

Great, thanks Blooz.

I guess theres nothing I can do but wait for the NO2 drop then

Typical - watch it clear up on Monday just so I'll have to wait another week before I can get to the LFS for my new stock!

 

[Wanda hornsey]

Make sure you keep feeding with ammonia tho all all the "good" bacteria in your filters will die

 

[bobf]

Make sure you keep feeding with ammonia tho all all the "good" bacteria in your filters will die

Thanks Wanda - will do.

That was what I was a bit worried about and if creating even more NO2/NO3 (as a by product of feeding the bacteria) would inhibit the NO2 drop off. Seems not, then!

 

[BHornsey]

Hi.

There was a very interesting article on FritzPet's website (Do a google on fritzpet) which gave a lot of info on Nitrifying Bacteria. I tried to find it again but it must have been moved so I can't post a link.

Basically, nitrifying bacteria grows more slowly than the ammonia reducing bacteria. The best growth rate occurs at a temperature between 25° - 30° C so it might worth running at higher temperature than normal whilst cycling.
Nitosomonas growth is slowed by pH levels below 7.0
Nitrobacter growth is slowed by pH levels above 8.0
and all nitrification is inhibited if pH drops below 6.0

Another fact I discovered is that nitrifying bacteria require phosphate (PO4) for certain cellular functions so a stalled cycle can sometimes be caused by PO4 absense (especially if RO water is used - common in marine setups)

Anyway, it often takes 10+ days after the ammonia drops for NO2 to drop off. Just check some of the above to ensure optimum growth of the nitrifying bacteria.

Phew !!

Brian

 

[Squid]

Thats useful information Brian.. in fact that explains why my cycle halted when my ph went really low, and a water change kicked it back into action..

Cheers
Squid

 

[BigIan]

yea thanks brian.

Does any one know if the cycleing process makes the PH of your tank drop?

 

[bobf]

Hi Brian and thanks for all that - v useful.

As it is I have the temp at about 84/85 to speed things a bit.

Interesting comments on ph and stalling the process. My tap water is around 6.5 ph but the tank I'm using has crushed coral and limestone based rocks (for Mbuna). This raised the ph to about 8 when I first put the water in. I recall reading on the fishless cycling guides that adding ammonia raises the ph so haven't bothered checking since.

Not sure if the process (ammonia aside) would affect the ph BI, but guess it's all over the place at the moment anyway?

Ten days sounds about right - think i've had the NO2/NO3 spike for about 5 days so far.

 

[BHornsey]

Hi.

Can't be certain but I think that ammonia does raise pH a few points. I noticed a slight increase in pH (up about 0.6) the last time I cycled a tank.

My last tank, ammonia spiked and dropped after only 5 days. It then took a further 8 days for nitrite to drop. I did a few small water changes when I noticed nitrAtes passing the 100 mg/L mark.

I found The Krib (www.thekrib.com) to be a good place for more scientific information. It seems to be populated by people with more letters after their name than the alphabet !!!

Brian

 

[bobf]

Thanks Brian - I guess I better sit tight for a few more days then!

Never was much good at patience - "... are we there yet?"

I'll have to make some stick on fish so I can pretend!


Will have a look at the Krib later if I'm feeling brave...