Have just been looking over the info available on cycling marine systems in general, and just wanted to add a few observations here if i may on cycling methods....
To kick start a cycle we need ammonia....What is a very natural way to produce ammonia? yes, something rotting away....So, to start off the cycle, we need to provide the tank with a source of ammonia. This can be achieved by quite a few methods which are available to us...I think for the sake of new people to the marine aquaria, it would be good to quickly run through these and show some good points and bad points..
- Fish Cycling - The good old damsel eh? a little poop machine that is hard as nails...Produces ammonia via its excretion..ideal to kick start the cycle...Humain? hell no....Anyone ever had a fish die while cyling the tank? If so, have you ever cut the fish's gill covers off to reveal the insides?? Please do so..Look at the state of them, look at the damage that is caused by the ammonia poisoning....See how red they are from taking in the ammonia...then think to yourself, wow, did i do all that damage to the fish??? Simple answer...yes....So..Good points and bad points....Good in that its a very natural way to start the cycle...Bad points in that you are severly damaging the fish's internals...
- Raw Shrimp - This is about as easy and effective as it gets...We know that we need an ammonia source, so, lets create one by sticking a medium sized raw prawn or shrimp in some pantyhoes or fine mesh bag...suspend or drop this on the substrate and walk away....Pretty complex huh? Out of all the methods, i think this is about the safest and easiest method there is..all you have to do is put in there and it will do all the work itself....you dont have to feed it, you dont have to check its gill covers. All you have to do with this is monitor the ammonia with your test kit...Wait for the ammonia to reach about 4 - 5ppm and then simply take it out and throw away...Job done...The good points are that its natural, safe, effective, no harm to an animal..The bad points, well, realistically, there are not any bad points. If anything, the smell that can be generated from the rotting can cause a bit of a smell. If thats the only kind of bad point, well, it aint that bad at all really is it?
- Fishless Cycling - Using this method is also quite effective, however, i feel that this method does have some short falls. This method involves using just live rock and live sand to cycle the tank. This occurs by relying on any dead organics rotting away and creating the much needed ammonia source. The area where i feel this falters, to a certain degree, is the level of usefull bacteria that is available in the tank. You may of noticed above on the prawn/shrimp method, that i said take out the shrimp at about 4 - 5ppm...Well, when using the live rock and sand method to cycle the tank, "normaly" you will only achieve a level of ammonia at around 1 to 2.5ppm before the nitrous bacteria start to convert the ammonia into nitrite. So, what effects / differences does this have compared to the raw shrimp?? Well, the main one is a conciderable difference in the level of usefull bacteria in the tank. For me, starting a new aquarium, i want to have a good level of usefull bacteria already present for when i start to introduce fish. Otherwise, you are relying on the bacteria level adapting straight away if you add a heavy excreting fish / messy eater. Good points of this method...Well, in all practical terms, exactly the same as the good points of using the raw shrimp / prawn..Bad points of this are that i feel you do not create as much usefull bacteria..For me, thats quite a bad point.
- Pure ammonia - Yet again, another effective way to start the cycle. The main difference with this method, against the ones above, is that the cycle will start instantly...Yes, you could think along the lines of using pure ammonia as a kind of speed cycling product. A quick word of caution here on the ammonia to be used. If / when you come to use this product, we need to ensure we are getting 100% "pure" ammonia. A quick test for this is too shake the bottle. If the ammonia has purfumes, additives etc etc (basically anything up and above 100% pure ) it will foam. Pure ammonia does not foam. So, thats quite an important point to keep in mind. To use this method, you simply add drops of pure ammonia to the tank untill you see the nitrite rise and peak. This is done repeatedly over a period of a week. I would advise a syringe or dropper to add the ammonia to the tank. How much you add varies. You keep adding ammonia untill it reads about 4 - 5ppm on the test kit. Make a note of how much ammonia is required to achieve this ammount of ammonia on the test. Keep repeating this process every day, or even every two days untill the ammonia is converted to nitrite within a period 12 hours, then your done with the ammonia. Good points are that you can easily / quickly start the cycle...Bad points, well, the huge bad point for this method is overdosing..If you overdoes the ammonia, it WILL kill off any life on the rock.
- Fish food - This is yet another very natural way to produce ammonia, because the food itelf will rot away and generate the ammonia needed. This method is used / achieved in the same way as the shrimp / prawn method above. Good points are the same as the prawn / shrimp...Bad points, well, there are not any..
So, we have some methods for cycling our aquarium...Some good, some bad...
As has already been mentioned in this thread, the discussion of having something in your tank rotting, and that being either unhealthy, have bad effects etc etc..However, simple fact is, there is nothing unhealthy about it and there are no bad or adverse effects...Its mother nature doing exactly what mother nature does best...work her magic...I often ask people in dicussions on this subject, why do you feel its unhealthy or un-natural to have something rotting in your tank?? various answers appear like "well, its dirty and disgusting" or " something rotting away in the tank has to have bad effects because its decaying" and many other statements along them lines....Well, fact of life, this happens in the ocean, it happens in life around us...It's mother nature....
The question then does need to be asked..."Are any othese methods classed as speed cycling?" ....Simple answer...only one of them, in my opinion, the pure ammonia method. I think on this line because your directly adding an element to force bacteria to be generated, rather than it occuring under natural circumstances.
I hope this little snippet of info is of some use to new marine keepers..Keep in mind, that i state the above on my own personal experience of using all the above cycling methods at some point and reasearched all the factors involved with each method...