Shotgun Cycling

  • #1
Just finished building a 250g tank for my Oscars and crew to move into in a few months when they've gotten a lil bigger.
I have read that adding small amounts of pure ammonia to my water will greatly increase the rate at which my new tank will be cycling.
This is a method of cycling that allows the process to operate with no fish in the tank and cut cycle time in half.
It sounds good read off the paper, makes sense even. Once the bacteria start producing nitrate it's all good correct?
No loss of lab rat fish during cycling, and done in half the time. Sounds almost to good to be true.
Tell me your feelings on this. I've already been hated on by the jerk at my fish store for even mentioning this to him, but he's kinda...weird though, and
his opinion is not why I shop there. He's a creep, wrong forum for that so I'll stop.

Please let me know what you guys know about this method. Not looking forward to cycling this tank the same way all my tanks have been cycled.
  • #2
Yeh that's right a small constant supply of ammonia(about every 12 hrs) will get things going. Then the nitrites will start to appear followed by the nitrates. You will need keep adding the ammonia until you start adding your fish. Dont add any fish until you have readings of 0 ammonia , 0 nitrites, and below 10 nitrates. Then only add @2 fish every 2 weeks or else you may start a miny cycle. Hope this helps.
  • #3
Sounds almost to good to be true.
That's because it isn't exactly true. Yes you can add pure ammonia without fish in your tank to get it to cycle. No it will not take half the time. The good bacteria only grow when there is a source of food for them (i.e. the ammonia) and then they can only grow in size every 15 hours or so. So if you start with 1 colony of good bacteria, then in 15 hours you will have 2, in another 15 hours you will have 4, etc. And considering each colony requires a microscope to actually be able to see, you can quickly get an idea of why the cycle takes so long. In fact just doing the ammonia to the tank without fish, will take the longest of all the cycle methods. The only way to speed it up is either seed your tank with a filter, rocks, sponge, etc. that has been in a fully cycled tank for some time. This will have the good bacteria on it already and mean that rather then starting with only 1 colony you start with hundreds. The only other proven method is by using Bio-Spira, but that is hard to find in a lot of local pet stores, and buying it online is very expensive because it has to be overnight shipped. Also if at any time in it's life it's been allowed to sit outside of a refrigerator then the good bacteria most likely died and won't help at all.

All that being said, using pure ammonia (or fish food) without fish in the tank is the best way to go about cycling your tank (unless you have access to good bio-spira) because you don't have to worry about water changes or anything till your tank is fully cycled. Using pure ammonia you need to add 5 drops for every 10 gallons water in your tank every 24 hours. Test your water and when you start to see nitrites you can drop the level down to 3 drops per 10 gal each day. Once you reach the end you will very likely have a lot of nitrates in your water. At this point you need to do at least a 25% water change and quite possibly up to 50% depending on the level of nitrates in your tank. You will want to be in the 10ppm range before adding fish. If you want to use fish flakes, then you add a pinch every 12 hours (when you wake up and before you go to bed works well) to the tank and when you get to the nitrate phase you will need to do the same water change listed for the pure ammonia. Good Luck!
  • #4
I don't think that using the ammonia method will shorten your cycle time, although it might.

however, one benefit of using ammoina to cycle (with or without old filter media) is that you can add a full bioload right away (well - right away after cycling).
  • Thread Starter
  • #5
Thank you for all of your responses. I'll start the shotgun next week when I have all accessories needed and operational.
I'll be starting a log of my shotgun, if I can find a place for it, if anyone's interested. I'll post a link asap.

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