Hey wuvvy!
I have a Vortex Diatom. LOVE it
However, I wouldn't want to rely on it as my primary filtration method. It's more of a good cleaner upper/ polisher. Here are a few pluses/minuses in my own personal experience/opinion.
Pluses - NOTHING makes your water sparkle like a diatom. NOTHING. Your water will shimmer and you'll be amazed that water can actually look that clean.
- it filters out EVERYTHING, particularly ich and other parasites. I've successfully ridden a tank of ich by using the diatom and nothing else (not entirely true, I suppose, as I use salt in my tanks as well).
- if you ever need a quick clean up... ie. Jenica wanted to help feed the fishies and dumped a mega size can of flake into the tank... the diatom will suck it all out within minutes (maybe an hour on a 120
)
- it's a high quality product; well made, works like a charm, does exactly what it says it will do
- it creates a ton of current and water agitation (could be a minus, depending on your fishies)
Minuses - where I live, diatom powder is more precious than diamonds!!! You shouldn't have that problem, living so close to Florida, where vortex is located. Ordering online is a nasty option for me in this case... the weight of the powder would make the cost of getting it across the continent a little bit extreme.
- if you're running it non stop, you have to recharge (replace the powder) CONSTANTLY. Like... two days after a fresh charge of powder, it's time to recharge. Recharging and priming is a bit of a messy, drawn out procedure (coming from somebody who just shoves a bunch of filter floss in all her filters)
- it's pretty loud (again, if I think one of my filters is too noisy, I replace it... I'm not fond of loud filters)
I totally recommend the Diatom, but not as your sole or primary filtration method. I use mine if I, say, stir up the substrate really well in a tank. I'll stick in the Diatom and let it clean up the mess I've made. Or if my fishies seem a little unhappy... I'll do a good w/c and run the diatom to sparkle things up a bit.
Hope that helps!!