Re: Vermiculite, Ideas and Input

Subject: Vermiculite Substrate 


> > Have other people had success with vermiculite long term?  I'm glad your
> > tank is doing well, and hope it continues to, but a two months, it's har
> > even settled in yet!
> True enough. How long does it take for the effects of anaerobic decay to
> show up? In a correspondence with Shaji some time ago, he said:
> "I used it in a 55 gallon tank.  The bottom third
> of the substrate was equal parts by volume of potting soil, peat and
> gravel.  The rest was washed gravel.
> The substrate did go anaerobic ( I could see the bottom of the tank
> darken) for two or three months, but after that, everything was fine."

From a purely personal perspective, I consider any tank under a year old 
still in the "experimental" stage.  Between one and two years, I allow some 
guarded enthusiasm.  When a tank remains stable and grows well for a 
_period_ of years, I consider a method successful (at least under those 
particular conditions<g>)

Subject: Just an Idea


> Along with plants I'm interested in Reef aquaria also.  Friend of mine 
> jsut set up his reef tank using this substrate method which optimizes the
> biological filter.
> It consists of multiple layers of different material.
> The bottom of the tank is empty, he placed empty cassette case on the 
> glass floor, on top of that he added egg crate, also known as light 
> diffusers for flourescent lights.   On top of that he add a layer of 
> screen door screen.  Then a layer of crushed coral, then two layers of 
> nylon screen, then a layer of finely crushed coral.

My understanding is that the purpose of this method is the reduction of 
nitrate.  This is not a problem in a well balanced healthy planted tank, so 
the goals are not the same.
> What does this mean for plants...well.. How about the same thing with 
> different substrate.
> Use the light diffusers, first layer of screen, then a layer of laterite,
> then a screen, or a layer of thick pebble/gravel, then several inches of 
> fine sand or small gravel.  
> My thought would be to run tubing down underneath the light diffusers to 
> force warm water or just a power head.   The water from this would be 
> from a sump. 

Someone else in the group is working with a similar RFUGF system where they 
are nutrient loading the substrate in this manner.  They have not had their 
set up going too long, so the jury is still out.  I run a 55G tank now over 
a year old with a UGF plate covered with fiberglass screen.  Over it is a 
fairly standard substrate of 1" of #1 gravel with laterite covered with 2" 
more of #1 gravel.  The UGF is run by small heaters in the uplift tubes 
which move water very slowly through the substrate, replacing trace elements 
with those added to the water column on a daily basis.

>In the sump you could either just add your fertilizer drops
> or how about a laterite bed that you could replenish.  Use light 
> diffusers to make several layers and have water that would flow through a
> bed of laterite that can easily be removed and replaced.  The water 
> (hopefully rich in iron) is pumped underneath the substrate and into the 
> laterite there.

First, laterite with water pumped through it at any speed makes a _huge_ 
mess!<g>  Second, the whole point of laterite is that it acts as an 
attachment point for trace elements, and HOLDS them in the substrate where 
the roots can get them.  Even if pumping water through the laterite could 
remove these nutrients, (which I doubt... it would just move bits of 
laterite around) what would be the point of removing them from the laterite 
just to force them back under the substrate and back into it?

BTW, by flowing water under the UG plate, it is no longer an anaerobic area 
for nitrate reduction, which also negates its purpose in a marine tank.

Subject: Input requested on new set up...

> Lighting:
> To illuminate this mess I've chosen 36" 95 watt VHO flourescent tubes
> coupled with the IceCap Electronic ballast.  After asking about them a
> few weeks ago I received several positive responses from folks claiming
> high levels of satisfaction.  I have not decided on the types of bulbs
> yet, but at least two of the bulbs will be URI AquaSun VHO bulbs.
> Although I purchased 4 of the AquaSun's I will most likely want to mix
> another type of bulb to either improve apperance or cover other specra.
> Since the IceCap allows you to mix VHO and normal output bulbs I feel I
> have a lot of flexability.

I tend to agree that for a high tech tank, you are not over-lighting, 
although you could probably get by with less if you chose to.  However, I 
question the use of 36" tubes over a 4' tank.  You will have dim areas 
without need, since 4' tubes would fit.  Also, you will pay the same amount 
for 3' tubes that you would for 4 footers, and get less light in the