Is it beneficial to ad water from an establishe tank to a cycling tank?

[TonyInVa]

Is it beneficial to ad water from an establishe tank to a cycling tank? The tank is about half way through the cycle. Nitrites are still coming down

I figured adding some of my water to the cycling tank would boost the good bacteria.

[WheresTheReef]

I don't think it would help much if any. You will be better off seeding with a piece of live rock from an established tank. This will definitely speed up your cycle.

[Bruleyii]

Most of the bacteria you find that's beneficial is on surfaces. That's why porous rock is much better than solid rock.

[WheresTheReef]

Most of the bacteria is on surfaces not the water.

[TonyInVa]

Thanks. Given live rock already.

[Coral Hind]

I always used old tank water but that doesn't make it right. I figured no sense in using new water just to have it go bad in the cycle process when there is really nothing in the tank that needs the trace elements in newly mixed water. Once the tank is ready for inverts, after months of cycling, then I do a large water change.

[sen5241b]

I've done several tank upgrades sand has a lot of beneficial bacteria in it as does the rock. I've heard the water itself has little.

[TonyInVa]

I always used old tank water but that doesn't make it right. I figured no sense in using new water just to have it go bad in the cycle process when there is really nothing in the tank that needs the trace elements in newly mixed water. Once the tank is ready for inverts, after months of cycling, then I do a large water change.

Makes sense. Maybe not from a bacterial perspective. 

[treesprite]

I like Coral Hind's explanation for the use of old water. I also agree it won't help with bacteria much.

 

Sometimes if a person is expecting a move to a new tank and won't be using well established rocks, it is a good idea to stick pieces of sponge in the old sump and leave them there for several weeks, then put them in the new system to seed bacteria. (I generally just use all my existing rock, and put my livestock in the tank without waiting, which has never caused me any problems, but that is without very drastic increase in system size, and with a relatively light bioload).

Edited October 8, 2017 by treesprite

[madweazl]

From one of Randy Holmes-Farley's "questions of the day."

 

Here are the calculations based on this article (others have results that are not too dissimilar):

http://science.sciencemag.org.sci-hub.cc/content/357/6352/646/tab-pdf

Bacterial cell density above coral reefs: 600,000-800,000 cells per mL (Figure 2, circles)

Let's use 600,000 cells per mL

The aquarium in question is a 120 gallon tank (OK, might have less volume, but we'll use the nominal volume) so it holds 454 liters, or 454,000 mL.

Thus the total bacteria in the water is about 600,000 bacteria per ml x 454,000 mL = 2.7 x 10^11 bacteria.

How many fit on the glass? Obviously it depends on their size, and whether they "spread out" on the glass, but let's just take it simply.

Size of Suspended Bacterial Cells and Association of Heterotrophic Activity with Size Fractions of Particles in Estuarine and Coastal Waters
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC240350/pdf/aem00152-0165.pdf

We'll take their value for the average bacterial volume of 0.078 um3. Let's press them into cubes so they have side dimensions of 0.43 microns (giving a volume per call of the 0.078 um3).

When stuck to a surface, they occupy an area of 0.43 um x 0.43 um = 0.18 um2, or 5.5 bacteria per square micron.

How many square microns is the glass surface area?

we have the following:
front, back and bottom of 122 cm x 61 cm (4' x 2') = 3 x 7442 cm2 = 22,326 cm2
2 sides of 61 x 61 cm = 2 x 3,721 =7442 cm2

total surface area = 29,768 cm2

How many sq microns is that?

29,768 cm2 x 10,000 microns/cm x 10,000 microns per cm = 3 x 10^12 um2

At 5.5 bacteria per square micron, that gives us a total packed surface of 5.5 x 3 x 10^12 = 1.6 x 10^13 total surface bound bacteria.

Surface = 1.6 x 10^13 bacteria
Water column = 2.7 x 10^11 bacteria

So there are 60 times a smany on the surface. Even if the bacteria spread out on the surface, there may still be more on the surface. But it is close.

 

 

While there are substantially more on the surface of glass (and rock, sand, etc.), it certainly looks like there is a significant amount of free floating bacteria. 

[Origami]

From one of Randy Holmes-Farley's "questions of the day."

 

 

While there are substantially more on the surface of glass (and rock, sand, etc.), it certainly looks like there is a significant amount of free floating bacteria. 

Cool! Thanks for sharing that RHF contribution. I'd not seen it before this.

 

And, as you've noted, that calculation only considers bacteria on the glass surfaces in an aquarium - not on other surfaces inside such as rock, sand, etc.