Old timer with filtratration question

There is really nothing wrong with a UGF, as long as it is maintained properly. An air powered UGF is an extremely cost effective solution. Powerheads cost more to run and more upfront, but that's how I prefer to run my UGFs...and I still do use them occasionally, such as to run outside aquariums.

If you vacuum your gravel with every water change, and redo your tanks about once a year, I can't see any problem with you using an undergravel filter. However if you don't, then chances are the UGF is actually making things dirtier and not cleaner. UGF does one thing and one thing only - provide biological filtration. It doesn't polish the water the way an external filter does. The carbon inserts for the uplifts are a joke, that tiny amount of carbon won't do anything except for maybe a 10 gallon tank.

Air pumps are kind of old fashioned and not used much any longer, except people use them for sponge filters often. Have you ever used a sponge filter? If you don't mind the noise of an air pump, you might want to give one a try. If you search eBay for XY sponge you will see how cheap you can get a sponge filter for, and they provide excellent biological and supplemental filtration. You can take them out and rinse them in aquarium water as needed...they will clog at different rates, depending on your stocking and feeding. They are basically a must for fry rearing tanks!

A cheap canister such as this:
http://www.ebay.com/itm/PERFECT-AQUARIUM-CANISTER-FILTER-SYSTEM-MEDIA-265-GPH-/190598098063
Should be able to take care of your 75 gallon tank with the Emperor 280 alongside.

Mostly, the drawbacks of UGFs are the difficulty in cleaning, the lack of flexibility, and the limitations they pose (can't do planted tanks, can't use media, etc.) Many aquarists now favor the more natural look of sand, and sand and UGFs don't generally mix well.

If you have the equipment, use it. UGF's are still used just not the fad filter. Read up on RUGF filtration. A different spin on an old but efficient method.

My 75 has an AC110 on one end and a 280 on the other. Just because I had them on hand. I am not someone to follow the crowd and look for the method that works for me. If you are subject to power outages, I would go with the UGF or sponge filters as you can operate more filters on less power. There is absolutely no reason that says you must use a particular style of filtration.

I'm a bit old school myself and I usually defend the age old, lowly under gravel filter. In the days before bio-media and canister filters, when "bubble up ruled", the UGF was a most excellent biological filter. I think the UGF fell from grace simply because IF/WHEN the filter media (gravel) is not periodically cleaned, the UGF can become a nitrate factory, plug and foul the tank. There is also concern that in the face of a power failure, anaerobic bacteria can quickly take over in the gravel and produce poisonous gases.

Also, I've recently been exploring 'deep' sand beds, so I suggest you set the UGF filter aside and use either an AquaClear HOB* or a canister filter, with mechanical and bio-media. This can be augmented with a 2-3" gravel, sand or gravel/sand substrate mix (as a significant amount of bio-filtration occurs in the substrate.
* I suggest the AquaClear because it's design allows US to decide the type and amount of filter media. I am not a fan of cartridge power filters.

If you're 'old school' gets the better of you (I understand) and you decide to use your UGF, just be sure to routinely (e.g. weekly) gravel siphon to keep the gravel as free of detritus as possible. Doing this will better ensure continued trouble free performance - failure could spell disaster.
Also, be advised that to a degree, UGF use, since the gravel must be cleaned, does not lend itself well for living plants.

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We were big believers in UGF too but don't use them any more for several reasons. Tubes are ugly. Even with good vacuuming there's quite a bit of crud trapped & constant water movement can keep DOCs high (dissolved organic compounds). Plant roots clog them & moving plants rips off a lot of roots that stay under the plates decreasing flow & trapping crud. I mostly use sand now. Fish can get under the plates. Pumps are often noisy.

But all that said, I wish I'd have tried RUGF or even powerheads, we were strictly airstone & pump users. I still have a few tanks' worth of plates etc, I can't throw them out, I may try again someday, lol.. Plus the power outage issue is something I think about more these days. I have 1 battery powered airpump, way not enough for the 8 or 9 tanks I had set up all over the house.

I use Aqua Clear & Whisper HOBs (some from UGF days!) & Rena XP3 cannisters, 2 filters on most tanks. I like the ACs media versatility better than Whisper cartridges (even with DIY media) & easier cleaning than Renas.

I have several tanks that are RUGF - Reverse flow UGF. I use Penguin 660r powerheads to push water down into the plates and up thru the gravel. You may still need to gravel vac, but not nearly as often. Mine often go 6 mos or more without a vac...tho they are filthy when I do.

I have a 40 breeder in a bedroom that has 3 660r's on it + a power filter. If someone is staying in the BR and objects to the filter noise I can unplug it and the powerheads continue to run quietly.

In my 90 (same footprint as 75G), I use 4 660r powerheads + a medium sized power filter.

Plants...I have no problems growing anubias, crypts, and Java ferns in my RUGF tanks...roots may grow down into UGF plates, but if you dont rearrange your tank frequently that's not a big deal.

and...a vote for deep sand bed...
I have a 75G deep sand bed tank. I used a mix of 2/3 pool filter and 1/3 play sand, ~4" deep. The substrate requires almost no maintenance. You do have to provide adequate filtration tho. Mine is lightly stocked and planted, I have 2 large sponge filters and a medium size power filter that do the job.

I have no doubt the reverse flow under gravel filtration lessens the gravel maintenance. The rub is that by the time we add the cost of the (2-4) power heads to the UGF, we're getting very near, or at, the cost of a decent canister filter. The very reason UGF's were popularized is because they were extremely economical and provided bio-filtration like few other filters of the day.
In light of the other filter options and bio-media available these days (and the potential pitfalls), the UGF really belongs in the museum...right next to the bubble up HOB and the corner filter.

Well, if you have the stuff, I would try the reverse flow under gravel method. Then I would probably add a good hob or a canister filter to help suck up anything that is pushed out of the gravel by the reverse flow system. Hey, now I know what I want to do for my big tank when I get it I hate gravel vacing because I am not very good at sucking most of it up. I often cause a bacterial bloom during my gravel vacs. (at a minimum every 2 weeks, but normally once a week or more) I think part of my problem is having such a small intake thing and the hose size. I need to get a bigger one and maybe even get one of those ones that hooks up to the sink and does all the work for you (other than moving the vac itself) But, I dont know if those come small enough for my 10g tank to really be worth it. Def worth it for a bigger tank though.