Hi Gloria!

Bogs in hot climates are difficult. Your biggest challenge will be keeping it cool enough to function; either that or stock it with tropical water plants such as lotus, bamboo (in pots! Bamboo roots will rip right through pond liner) and tropical water lilies. Look around for heat-hardy marginals, and dig it somewhat deeper than you would in more temperate climes. Make sure that it gets partial shade at the peak of the day.

"Bog" filters are not true bogs, since they do not contain peat. What you will be constructing will be closer to a marsh (swamp without trees), but with brisker water movement. Plan on about one-third of your water flow diverted through the marsh and the remaining two-thirds over your falls. You can play with this ratio to suit your own tastes. Do not rely on the marsh to supply all your filtration. You'll still need higher-tech biological and mechanical filtration to keep up with your koi. Your marsh will help with nitrates and nitrites. Sludge, algae, dissolved organics and ammonia will still be the responsibility of your bottom drains, prefilters, protein extractor and bioconverters.

Don't be tempted to floor your marsh with gravel. You'll just have to get into the marsh to de-sludge it twice a year. Big, shallow pots full of plants on the bare-liner bottom will keep your maintenance to a minimum.

Bob Passovoy