I had four holes drilled into the bottom glass. two for the filter intake
and outtake, one for a pass-through for wires, and one for a soil drain.
You can
probably
skip the filter holes and wire pass-through if you want, but you must have
some sort of soil drain. An alternative design is a dry well, where a length
of PVC pipe can extend above the soil level and essentially evaporate the
water that settles below the dirt level. However, this will only compensate
for small amounts of water. You will be amazed how much water settles in
the dirt section on the tank. Even without watering the plants, I typically
drain at least a half-gallon of water a week out of the soil drain. I'm sure
most of this comes from humidity and spills over the edge of the glass from
the water section. But in any case, be sure to include some sort of a soil
drain or after a while, your plants will surely rot away while they lose
the battle to transform into bog plants.
To adapt your drilled tank holes to your equipment, you'll need PVC bulkhead fittings. It is a good idea to buy these at the aquarium store where your custom tank was ordered, because you have to match up the outside hole sizes with the manufacturer of the fittings. Otherwise, buy the fittings ahead of time and take them with you when you order your tank. You also need PVC ball valves for each hole, which you can buy at a plumbing shop or a hardware store. Do not skimp on these. I cannot tell you how many times a piece of tubing came loose while working on the tank and the ball valve quickly stopped a potential torrent of water from reaching the rug. Consider these safety valves, even though you may rarely if ever use them.
The Land Section
For the land section, I first put in about 4 inches of lava rock. I
chose lava rock for its light weight, but you can use any kind of rock you
want. Next, I used
packaged
potting soil and filled the land section about an inch from the top of the
dividing glass. For the 30" wide by 6" deep section of this tank, it took
about 12 dry quarts of potting soil. I have not found any significant differences
between brands, so buy what ever is on sale. The photo to the
right shows the lava rock in place with the wires for the heater and grounding
probe coming out of the bulkhead for the wire.
The Water Section
For
the water section, start with a fine gravel. Do not use marine aquarium sands.
Use the smallest grain size gravel your aquarium dealer has for freshwater
aquariums. You may be tempted to go to a building supply house and buy gravel
for half the price, but be aware that many impurities (such as metal shavings)
may be present that will adversely affect your water chemistry. Pay the extra
bucks and buy it from the aquarium store.
You want a total of 5-6 inches of gravel depth. Start by adding two inches of gravel, then add some garden soil or clay dirt to a depth of ¼ to ½ inch. This will provide a rich medium for your aquatic plants. You may also add some gravel conditioners such as Tetra's Helena Initial D, which I highly recommend. If you've added any water so far, the tank now looks like a mud puddle. Don't worry, it will clear up once you get some circulation going.
The Filter
There are probably more debates about filter equipment
than
any aspect of the aquarium hobby. The short and sweet answer here is to use
a canister filter. I used a
Fluval 203,
but any reputable manufacturer's filter will do. I have had a paludarium
set up in the past using a wet-dry filter, and do not recommend these. Even
if you use DLS material instead of Bio-Balls, you will still have a severe
CO2 outgassing problem which means that your aquatic plants will
be very unhappy. The "hang-on" variety of filters are not suitable for
paludariums due to the water level not present at the top of the tank. But
the good news is that your filter can be much smaller than you think. For
example, the 70 gallon tank used in this setup only holds about 20 gallons
of water, so you can get away with a smaller and less expensive filter. The
same holds true for the water heater.
Lighting
You needs lots of light. Don't settle for the standard aquarium light and hood combos. For this setup, I used 4 20-watt fluorescent bulbs. You can buy the ballasts at a hardware store and end caps at the aquarium store and wire them up yourself. But if you're electrically challenged, go to an aquarium store that specializes in reef setups and buy a multi-bulb reef fluorescent fixture. You might be able to find something at a hardware or lighting store, but stay away from the so called "shop lights" because they severely limit light output and bulb life.
