Is There Beneficial Bacteria In A Tank With No Substrate?

[nLinked]

While my main tank was under repair for 2 weeks, I had my fish in a smaller tank. The spare tank has no substrate or decoration apart from 1 rock just to keep the fish calm. I was thinking of filling the main tank with all of the water from the spare tank once the repair is complete. Is this a good idea? Will there be beneficial bacteria in the current spare tank's water that I could do with in the new tank? Or is very little goodness in that water and just more ammonia?

 

[N0body Of The Goat]

While some bacteria may roam in the water and be on plants/furniture within a tank, most of the colony keeping the tank safe for fish will be in the filter or namely its media (sponges/pads/ceramics).

 

[waterdrop]

Agree - Nearly all the bacteria that are going to give you any benefit will be anchored to the media in the filter being used. Even in established tanks the filter based bacteria will greatly dominate, despite the fact that there will indeed be some on the substrate, the plants, the tank walls and the insides of filter hoses. At times there can be situations where the sudden loss of those "peripheral" bacteria might make a difference but those instances are rare and the filter media remains the main thing most beginners should be worrying about.

As far as -using- the water the fish have been temporarily in, there could be other reasons why it might be handy for you. Fish always acclimate to the water they are in in several ways. Temperature and hardness are a couple of the main ones. The various dissolved minerals (that help to make up the hardness measurement) can move along with the fish to the new tank if you also transfer the existing tank water and it is a significant volume of new tank water. On the other hand, if you are using relatively frequent water changes to keep the characteristics of your tank water similar to your home tap water (or whatever your "source" water is) then it won't really matter that the fish move to a tank of new water (normal guidelines for acclimation should still be followed of course). The move in that case will not be much different to the fish than a typical weekly water change.

Ah well, just some ramblings...
~~waterdrop~~

 

[Yanks15]

Hey waterdrop, glad to see that you are still kicking around here. You gave me a lot of help a few years back. I used to be 22Rocket when I lived back in Raleigh. For some reason my original screen name was deleted at some point in the past 2+years so I started up anew. Back then I kept tropicals and gold fish. Now I'm putting together a Mbuna tank to get back into the swing of things. Anyway, I'm glad you're still around.

 

[TwoTankAmin]

Actually, in most tanks there will be a reasonable amount of bacteria outside one's filter. It will be on any hospitable hard surface in a tank. However, the critical determinants of how much and where the bacteria may be is a function of two factors. Bio-load and hospitable surfaces available. Hospitable means good circulation so a constant supply of food and oxygen are available. The more bacteria one needs, the more places it is likely to live, especially if they are hospital surfaces.

In some tank situations one should actually find more bacteria outside of the filter than in it. A tank where maint. is lax and media is allowed to glog regularly is not a hospitable place for the bacteria. So in a tank like that, the bacteria are going to be a lot of other places. A clogged filter may not be a good home but it will still provide circulation and oxygenation.

Bare bottom tanks are not the best place for bacteria to be living. However, the decor one may put into the tank should be. Rocks and wood can all house it.

It is also worth noting that in the scant amount of research into the nitrifying organisms specifically in fish tanks, samples of the bacteria to be cultured for the research are obtained from both the filter media and from the substrate. Lastly, how many threads have we seen where somebody reports having a mini-spike/cycle after they changed their substrate?

It is an over simplicification to say there is not a meaningful amount of bacteria outside of ones filter(s).

 

[nLinked]

Thank you all for the info!

 

[waterdrop]

Yes agree, very good comments by TTA. Bacteria certainly do not "choose" filters, they simply multiply where conditions are right with attachment surfaces and a flow of source materials like oxygen, calcium and of course whatever their main food-like source is, ammonia or nitrite for instance. If one has one of the situations described by TTA then take note. And I also agree, we do from time to time see situations where the rapid removal or disturbance of biofilms that have established outside the filter box are the cause of a mini-spike -- this is yet another good thing for beginners to learn about and be aware of. Overall, a good description of some of the tank situations we see at the statistical margins, if not the usual majority of tank situations.

~~waterdrop~~