2 x fishless cycle questions

[krawhitham]

Good afternoon,

I have a couple of questions regarding a fishless cycle:

1. Is there any benefit to running/not running lighting when cycling? Do the bacteria need/hate light?

2. Should I cycle with a full tank of water or is there any benefit to having it half full (higher concentration of ammonia?).

Thanks,

Dean

[Shilo]

I never really finished my cycle before putting a fish in but my thoughts are:

1, The largest population of bacteria in a cycled tank is in the filter system, there will be a good population in the tank itself but its the filter that you want the majority working away in so I wouldn't worry too much about the light in the tank. Your filter wouldn't have a light in it anyway.  Advantage of having it on is to make sure your timers & lights work over the month or so cycling and of course its needed if there are plants. Disadvantage is that it can give algae a head start but different types of algae will naturally cycle in a new tank anyway (e.g. diatoms).

2. You need to keep the ammonia under 3-4ppm regardless on how much water is in the tank, any more and the cycling will stop.  A full tank just means you have to top up more ammonia then a 1/2 full one but the parts per million will be the same.  Bacteria live on a surfaces and there are very little in the water itself. So the glass of the tank, the gravel, any decorations & plants etc will have bacteria growing on it. Majority of course will be in the filter where your media has an extremely large surface area (inside the pores etc)  The amount off water won't effect this much apart from the glass or decorations above the 1/2 way mark in the tank. Why not just set the tank up as you would if you had fish in it (full with lights on), this way you can suss out any problems before you stock it.

Some things I've just gone through trying to cycle are:

 Patience, patience and more patience. It will happen but takes awhile.

 Heat is essential.  I tried cycling at 15C (the temperature my tank will be with fish in) but nothing much happened until I threw in a couple of heaters and got it up to 28C.

I tried Seachem Stability but that was over the cold period. Once I heated the tank I had both Nitrites and Nitrates showed up with the ammonia drop, normally the Nitrite is meant to spike before Nitrates appear.  I have a feeling this was because I had introduced a large amount of Nitrate producing bacteria via Stability so it may have had some effect. 

 

Edited September 20, 2015 by Shilo

[krawhitham]

Thanks for the detailed reply

[PowderPig]

Hi Dean, how are you fishless cycling your tank? pure ammonia of fish food? I believe a combination of the two might be the best method.

What size tank are you cycling? unless its huge I think I'd full it up.

Providing aeration is also key as bacteria will multiply faster in well oxygenated water. Ensure good surface agitation and/or add an air stone if you haven't already. I found a good read on the subject here http://www.americanaquariumproducts.com/Nitrogen_Cycle.html

It's good to have a water test kit to track your progress. API master kit is recommended as it tests PH, Ammonia, Nitrite and Nitrate.

I just cycled an unplanted tank using the fish food method, lights off, but heated to 30°C. I added a small amount of flake food that I first ground to dust, every 2nd day, It took about a week for the ammonia levels to climb and another week or so for nitrite to climb, and just over 30days for nitrites to drop down to zero. I then did a 95% water change, vacuuming up any leftover fish food, lowered the temperature to 25°C and added some fish. They all look good and the water is testing perfect. Remember to always add dechlorinator (Seachem Prime or similar) to your water changes.

Once your tank is cycled add fish ASAP (after a large water change) to keep your filter fed. Once the filter is cycled it will need a constant supply of ammonia or the good bacteria will stave and die off,- fish waste will now be that ammonia source.

 

[krawhitham]

I'm cycling a 65L tank and have been adding ammonia (although I clearly added too much... lesson learned)

I will be keeping cold water fish so I do not have a heater and can't really justify buying one to only use for cycling. I have raised the outflow from my water pump as high as it can go to create a bit of a waterfall and oxygenate the water.

I'm fortunate in that there is no chlorine added to the water here in Napier, so that is one less thing to worry about

Thanks for your help

[PowderPig]

Okay, cool, I understand aerating the water is more important at higher temperature's so I'm sure you'll be fine in a cold water system. When I refer to "dechlorinator" I really mean water conditioner. Prime, for example does more than just remove chlorine. It takes care of chloramine and heavy metals, plus has the advantage of detoxifying ammonia and nitrite for a short period if you make a mistake and notice a spike in either of those two nasties. Plenty of people keep fish successfully without use of water conditioners but its handy to know about them IMO.

Have you managed to convert any ammonia into nitrite yet?

Edited September 25, 2015 by PowderPig

[krawhitham]

Have you managed to convert any ammonia into nitrite yet?

Sadly not, which is a little frustrating.

[Shilo]

Only been a week so still early days.  If I was you I would invest in a cheap heater, have read it can take 6 weeks or more in a unheated tank but half that time at 28C. 

[krawhitham]

So I'm getting nitrates and nitrites now

To minimise the risk of stress when I do add a few fish, should I do lots of small water changes? Something like 10% every 3 days?

[PowderPig]

You shouldn't need to if the tank is cycled properly. I'd just test the water every few days after adding fish to make sure the filter is processing everything as expected.

Adding the fish carefully is probably the best way to keep stress to a minimum.

[krawhitham]

Thanks again for all the advice.