[Schreckeng]

Hey, so I have a little 10 gallon that I'm going to change my substrate from gravel to sand.

Will the bacteria in my HOB filter be enough to prevent a mini-cycle?

(I have extra lava rock that's been in the tank for 3 months that I've put into the filter, it also has a bio-wheel.)

Any Information provided would be greatly appreciated.

 

[kcoscia]

You should be okay, but I would monitor for a mini cycle just in case.
I recently redid my substrate, kept filters wet/running and only had ammonia between 0-0.25, which resolved.

 

[lochaber]

I would think that the filter media would have more then the substrate, just since there is a constant flow of water through it. Bacteria in the substrate are going to be a little bit more limited in terms of access to both ammonia and oxygen.

Although, this is mostly speculation on my part, I have no idea what the actual ratio of bacteria in substrate to bacteria in filter is.

I also suspect that any ammonia you notice may be more due to stirring up pockets of organics, that decompose and produce ammonia, rather then loosing filtration capability.

Either way, plants should help, especially floaters.

 

[Sanchezdaminguez]

You could seed by using the hob filter and by re-using the water. Just make sure that you remove the water before unsettling your substrate as you don't want the detritus to get into it.

As for whether it will cycle is dependant on how big your bacterial filter is in the hob. You need enough bacteria to combat the spikes.

 

[Schreckeng]

Thanks everybody, I really appreciate all the input. I've got a bunch of fast growing plants, and I plan on removing water and fish. Before even touching the substrate to reduce ammonia chances.

Thanks again!

 

[Diana]

There is not much bacteria in most of the substrate. Poor water flow, so the gravel is too low in oxygen.

The greatest population of nitrifying bacteria is in the filter, especially with extra media and a bio wheel.

If you want to be ultra conservative you can skim the top layer of gravel (about 2 rocks thick) and save this in several mesh bags or nylon stockings. (well, cut up stockings).
Hang these in the tank and remove one per week for a month. This will spread out the loss of the bacteria.

There is not much bacteria in the water. These bacteria colonize surfaces such as all the filter media, rocks, driftwood, plant parts, ceramic merpeople and so on.

I have done complete tank changes (substrate, hardscape) with saving just the filter and that was a bit much. Had to stay on top of water changes.
When I do big water changes (pretty close to 100%) there is no problem at all. (except the fish flopping around- oops).

 

[Schreckeng]

Lol, thanks Diana