# Under Gravel Jet Question



## drbunson (Apr 19, 2011)

Hello

I'm looking to put in an UGJ set up in my 90gal FW. Question is How many Jets to use and How to arrange them? Also not sure what kind of pump to get. Read something about at least 125gph per jet? Thanks in advance for any input.

Bob


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## emc7 (Jul 23, 2005)

Look at 'powerheads' that have a 1" adapter. Penguin, Maxi-jet, others. I think you want no more than 10X turnover total thru a UGF (lower may be better), so 900 GPH max total. Look the pic of the UGF and see where the uptake holes are. You want at least one at each plate edge and possibly more, equally spaced. 

Consider reversible ones like the Penguin 660R that blow into the gravel rather than suck. Make for more 'prefilter' cleaner, but less gravel-washing.


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## drbunson (Apr 19, 2011)

emc7 thanks for the reply!

Plan on getting rid of the gravel and going to sand. So the UGF plate will be coming out and be replaced with PVC pipe. Hoping to reduce the cleaning of the base to as little as possible. From what I have read going to a UGJ setup with sand works well for this purpose.


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## AquariumTech (Oct 12, 2010)

Dont, undergravels are the worst idea for aquariums, ever.


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## emc7 (Jul 23, 2005)

I'm not going to get into the whole anti- pro argument. IMO, they are bad if you can't or won't clean the substrate properly or don't like plant roots tied around plates. And reversing the flow solves a lot of the obvious issues.

But I'm not sure how a UGF would work with sand. A reverse one blowing up could cloud the water and sucking crud down into it seems like it would be ugly.


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## AquariumTech (Oct 12, 2010)

Look, those are the only filters without media. Everyone SHOULD KNOW media is the heart of a FILTER! With that being said, well, use your common sense. Not to mention your gravel does the same amount of filtering on its own WITH OUT a ugf. I will leave it at that but most undergravels I have ever seen, are not compatible with sand unless you use air. Unless you dont mind broken powerheads.


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## emc7 (Jul 23, 2005)

With a UGF, the gravel is the media. So UGF have a large surface area for bacteria. When I see gravel w/o a UGF I think its a waste of potentially good media. Gravel w/o flow does NOT do the filtering work of UGF. Some bacteria will live on the surface, but only as much as can find food and oxygen and that is dependent on how much water is flowing by. It better then 'cycling' a bare glass tank, but really not much better. A tablespoon of gravel from a UGF tank will have more bacteria on it than all the gravel in a non-UGF tank. A UGF tank is a great way to have ready 'seeds' for cycling new tanks.

A neglected tank with a UGF is, IMO, no worse off than a neglected tank with a thick gravel bed without one and may be better off. Both with have uneaten food and fish poop decaying in the crevices and this will lead eventually to sky-high, off-the-scale, pH-crashing nitrates. But the UGF tank won't have any anaerobic decay and HS production. 

I find sand really annoying the way it grinds up impellers, but people with white sand do keep it clean because the poop sits on top and looks ugly. 

My take: If you have substrate, clean it. Without a UGF, keep it thin. With a UGF, keep the substrate clean and clean under the plate or use a reverse UGF and keep the intake sponge filters clean. Don't use UGF with nitrate sensitive fish like Discus. Don't use it with substrate-planted plants unless you don't rearrange your plants, ever. Don't bash people who use UGFs. We aren't idiots. UGFs are cheap, effective, biological filtration in an area of the tank that is usually wasted. They have serious drawbacks, but aren't "useless". Fish were kept effectively for decades before the invention of power filters and most of the anti-UGF propaganda you've read was written by the HOB makers.

Personally, I think UGFs are too much work for me compared to other options (bare tanks w/sponge filters being one). But if you want the look of a thick gravel bed, they are worth considering. And if ever you have to choose between UGF and no filter, go with the UGF and keep the substrate clean.


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## emc7 (Jul 23, 2005)

I think you can run current under sand with PVC and power heads, but it wouldn't function as a filter. You could do the 'river tank' thing with sponge covered intake(s) at one end and blowing Powerhead(s) at the other and a constant current flowing in the tank. But for stronger current, you'd want a substrate that wouldn't blow around. 

Sand on a UGF plate would just run through and fill the space under. Even PVC with holes, would need really small holes and large sand. There should be a way to make it work like pond filters do with big rocks, gravel of decreasing size and sand on top. But it would be a pain to clean.


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## AquariumTech (Oct 12, 2010)

Well, I meant that a ugf is the only filter that doesnt add media to your tank. If there wasnt enough bacteria (and etc.) on my gravel with no ugf, my tanks would have poop hanging everywhere. Most poop sinks to the bottom, even with the many filters on each tank. Anyways really all it does is enhance gravity, when really I would rather have that poop go into a filter where it is much easier to clean and "officially" remove from the tank. 

A ugf is also bad for anaerobic bacteria; obviously judging by the name of the bacteria. This bacteria is all so precious especially in freshwater where oxygen is much more abundant. This of course makes it harder for it to grow, with none to little flow going across the bottom without a ugf, this a much better way to grow this bacteria. Most people dont realize the amount of aerobic bacteria you need (on the other hand) is usually easily met, with a properly stocked tank. 

Not to mention the other limitations it puts on you tank, and the ugliness it adds. Like you said they also need to maintained. You are right that is pretty much the difference between it being just a pain, and it being counter productive. Not to mention when you do have to clean it, boy is that a pain in the ass. Not to mention dangerous for life in the tank. 

I have had my fair share of ugfs, and I used to believe it helped with other filters too. Until I took a good look, and really it did nothing in pretty much any situation. Then I did my research into them, looked at others results, not just testimonies from people that have been using them forever that have a pushed opinions not related to the actual facts. Not to mention I still spend quite a bit of money for my water testing for research of my own (not really with ugfs anymore as I know what they "do").

Im not saying you cant have a successful tank with one, just saying its a horrible choice especially for whats out on the market today.


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## emc7 (Jul 23, 2005)

I will likely never buy another UGF and have been taken them out of tanks (and the substrate, too) to make things easier for me. But as someone whose used them for decades, I feel compelled to defend them. Every so often someone buys a used tank with a UGF and fish. He gets on the boards and hears "UGF are evil, fish-killing, snake-oil" and pulls it out, thereby leaving the fish filter-less and dead soon. Any filter is better than none. 

And I swear there was less 'new tank syndrome" in the UGF age. You'd take a handful of gravel home with the fish. Maybe we just bought fewer fish because they used to cost actual money. We did see more 'old tank syndrome' where a proud "never had a water change" tank suddenly had all the fish suddenly ("for no reason") die after a few years.

Modern power filters are much more 'efficient', designed with all the latest data. But then they come with instructions to throw away all your media (so they can sell more cartridges) or simply quit working with no warning. Having a cheap, simple low-tech filter like a sponge, a box or UGF can save your fish when your high-tech gadget craps out.

I still have a few UGFs as second filters in tanks with gravel, big rocks and Mbuna. They keep dropped rocks from cracking the bottom of the tank and the ridges keep the rock piles from sliding.


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## emc7 (Jul 23, 2005)

Sounds like he wants to use the pump to keep the sand clean and blow water up through it and blow the crud where other filters can grab it, so the UGF debate isn't relevant. So sorry for the hijack.

If you keep the water flowing out the holes in the pvc, it should blow sand out and make 'smokey' plumes of sand rise up in the tank. Should be a cool effect. Keeping sand out of the filters and pumps will be the hardest part. And finding the right amount of flow to keep the holes from plugging without clouding the whole tank will take some experimentation. You should probably buy one of the more expensive adjustable flow pumps they sell for salt-water.


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## drbunson (Apr 19, 2011)

emc7 said:


> Sounds like he wants to use the pump to keep the sand clean and blow water up through it and blow the crud where other filters can grab it, so the UGF debate isn't relevant. So sorry for the hijack.


YES!!

My goodness ! lol Remind me not to use that three letter abbreviation again! ha

Any how I didn't plan on really drilling holes into the pvc. I saw or read something about having like 4 or 6 pop outs (jets) that would blow across the bottom. Just wondering if there was a preferred number of jets or config.

As far as the river tank, do all fish like that kind of current all the time?

Thanks to all!


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## emc7 (Jul 23, 2005)

bettas don't and other fish that live in stagnant pools and some lake fish hate current. But fish from streams, creeks, rivers, or oceans often appreciate it and some fish from fast-flowing water actually seem to need the extra aeration of constantly moving water. And there are fish that just sit still and let the water bring them food that just go hungry in still water.


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## drbunson (Apr 19, 2011)

I saw the river tank idea once awhile back and wanted to do it. But i notice my little barbs and tetra always stay in the calm corner of the tank. So i was thinkin they might not like that idea. Thats why i was thinkin jets so as to not have one massive current but still stir up the poo and such to the other filters.


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## emc7 (Jul 23, 2005)

I going to zip it now and hopefully someone with sand will answer you.


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## drbunson (Apr 19, 2011)

:lol::lol:

Thanks emc7 you have been helpful!

Does anyone out there have sand with pvc jets?


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