# using a foam or sponge



## killacross (Apr 29, 2010)

couple dozen views in the substrate section but no takers sooo....

so...after 1 year and changing my scape and changing my scape and changing my scape...my substrate is finally depleted and my plants arent growing (as fast as i would like...)

now...i could spend the $40 to jus buy new substrate or i guess get into a fert regimen

BUT

was thinking about something random...so now I ask you all to poke holes in my idea...and crush my dreams!

what is i used a piece of foam as the "base" layer of the substrate

something porous that roots could grow fairly easy in but that holds water well.

I was thinking that you put a layer of foam down...cover it with gravel and plant the tank. then using a flavor injector (the needle type that you use on a turkey at thanksgiving) and inject fertilizer into the foam. since the foam is thick...the fertilizer shouldnt leak back into the tank and the ferts will be kept in place for the plants to take up

it would be easy to "recharge" your substrate after all the nutrients are gone because you just inject it with new liquid ferts however many months


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## joshd (Oct 16, 2009)

killacross - 

that's an interesting idea and I hope that you do some experimentation with it. A couple thoughts/considerations I had were:

- the foam would have to be fairly stiff to avoid over-compression from the substrate cap and hardscape
-the foam would also need to be open cell to allow dispersion
-uprooting and moving plants that had strongly rooted in the foam could be quite difficult and may end with a completely mangled plant
-might be challenging to get stems to stick in it

These are just some of the thoughts that I had. You could experiment by trying it in a pot or shallow tupperware placed in your tank without making a full commitment.

Also, I have really liked using RootMedic root tabs to fertilize my substate. They seem to last a good long while, and they are pretty well priced. You can find good deals on them over at PTF.


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## joshvito (Apr 6, 2009)

You could always make fertilizer ice cubes and stick them into your substrate when it gets depleted.
(Stole this idea from Barr Report)


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## killacross (Apr 29, 2010)

@joshd

yea...I didnt think about compression problems...also, didnt consider that any scape would be more or less permanent

@joshvito

i read that thread here as well (ice cube tabs) and i agree..it would probably work as well


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## Diana K (Dec 20, 2007)

Probably do not need the foam. If you want to inject ferts that way just put the turkey baster deep in so you touch the bottom of the tank. Any plant substrate will be dense enough to keep the ferts pretty much out of the water column. Gravel would probably not be good this way. 

Osmocote in an ice cube or fertilizer tablets is a longer lasting solution than liquid fertilizers.


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