Vivarium false bottoms

[Narmster]

:
Ok i am new at the Vivarium thing , and i just dont get the false bottom.
My tank is around 25 gallons and i am going to put a waterfall, stream, and a good size pool of water (i will be putting tadpoles in there in the spring). I have heard that eggcrate false bottoms are great, but are they fully submergerd in water? If they arent then why do people put pumps in a false bottom full of air? What this the point of the PVC pipes? And when i put my pond should i put plastic around the edges of the eggcrate false bottom?
Srry for all the questions, but im puzzled. Pictures are VERY helpful

[mh32]

I'm fairly new also, but from what I understand a false bottom is basically to raise the substrate from soaking in the water. So everything under the eggcrate is water and not air.

So if you wanted a pond that was 4 inches deep your whole tank would be filled with water 4 inches deep (unless you have your tank divided). You would then put your false bottom at 4.5 inches so that you don't just have a muddy mess of sludge for your substrate.

A very basic explination.

Anyone correct me if I'm wrong but that's what I understand.

[Devil_Boy]

thats basically right. the false bottom keeps your substrate from being a muddy mess like said, it gives the substrate drainage. the pvc pipes are just cut to length and act as legs to hold up the eggcrate. you can put a pump in the water under the false bottom but the only problem is if it burns out or gets clogged it will suck to have to rip apart the tank to get to it, so its good to make it somewhat accessible.

Basically i cut out the same shape as my tank then put it in my tank, So now it looks like a raised floor with holes in it. then i decided where i wanted my little pond and i cut that part out of the eggcrate. i then sealed up all the edges with more eggcrate so you cant get underneath of the eggcrate. I THEN covered the whole thing in window screen and you can put the substrate on.

Hopefully that helps....

[Rainfrog]

Those are both really good responses. id say spot on. The reason for the 4.5 if you want 4 in depth is to prevent capillary action (water "wicking" up in to the soil). I like the idea of an easily removable area for a pump. I like to have a section of eggcrate cut separate from the rest of the floor to place over the hardware. On top of that piece I put one rock or a plant in a small pot, just something that is easily removed and does not require me to tear the whole thing apart to get to my pump/filter.