# Adding Undergravel Jets to Existing Tank



## RFan (Aug 4, 2014)

I'm considering adding an undergravel jet system to my existing mbuna tank. It's a 6 foot, 125g tank with gravel substrate. I've read the library article on the ujs and done some additional research. But I still have some questions and would greatly appreciate any advice before I commit to this.

1) My goal is to reduce the need for vacuuming each week. Will a ujs accomplish that.

2) My plan is to use flexible tubing instead of PVC b/c I think it will be easier to add to an existing aquarium. I got the idea here: viewtopic.php?t=221825. Any problems with flexible tubing versus PVC?

3) I've seen some people recommend drilling holes in the PVC and others recommend using jets attached to the end. Which is the best setup?

4) How many pumps and jets would you recommend for my tank? What brand and size pump is the best?

5) Do I need to add a filter to the pumps or will the gunk simply be swept up into my canister filters? If it goes into the canisters, will I need to clean them a lot more often to avoid an increase in nitrates?

6) Should the jets stick up out from the gravel or are they totally buried?

7) Does the flow created by the ujs bother the fish, especially the catfish and plecos that spend a lot of time on the bottom?

Many thanks for any help!


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## Deeda (Oct 12, 2012)

There are 2 articles in the Library about UGJ's, one is Here and the 2nd one Here. If you enjoy DIY projects, try installing them. Choosing where to place the UGJ's will depend on where you plan on stacking any rocks or other decorations.

1. It may reduce the need to vacuum but larger sized gravel can still trap debris.
2. Flexible tubing may be more difficult to stay submerged, it depends on how heavy it is.
3. I don't know.
4. Don't know.
5. Adding a sponge pre-filter to the pump will help catch debris but will need to be cleaned frequently to avoid clogging. Additional dirt and debris caught in the canister filter will require more frequent cleaning.
6. Jets are usually at or above the surface because the water flow will displace any substrate.
7. Any bottom dwelling fish will probably directly avoid the water flow from the jets if it is strong. Your other fish may play in the new water flow. You could also use the Search feature to see what other members experiences were with this project.


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## Mcdaphnia (Dec 16, 2003)

1) Properly "tuned", an UGJ will pile detritus up in more convenient spots, but it won't change how much there is.

2) Flexible tubing will work its way out of the gravel or sand faster than PVC, but both will lift out if not secured well.

3) Jets made from connectors and left unglued can be rotated to change the water jets to optimum for clearing the bottom of detritus and moving it to a convenient collecting site. If you just have holes in the tube, adjustment is more complicated.

4) One pump and three or four jets along the back of the tank where they can blow detritus out of the mbuna rock work. I like the Supreme Mag Drive pumps and a #2 should be big enough. If you like more current, add another #2 rather than going up a size or two.

5) A prefilter is a great idea. Have extras so you can slip a clean one on when you remove the dirty one. Because a jet system has laminar (smooth) flow, not much detritus will be diverted into the canister filters.

6) The jets should be even with the top of the substrate. If it's above it, the flow won't move anything and the tube will be unsightly. If you place the jet below the surface it will blow away the covering substrate until it is even with the top of the jet.

7) Most plecos enjoy current and will spend time in it if they have any attachment points they can latch on to.

Answers you didn't ask for but you might find useful....

8 ) UGJ are OK with sand but not gravel because detritus sinks into gravel and has to be "mucker-suckered" out with a gravel cleaner. Detritus rests on top of sand.

9) Wave makers are much more effective at this job than UGJ's. A timer creates turbulent flow that cleans a broader area and makes clean up much simpler. They are easy to adjust and being out of the substrate, easier to install. They are visible, but the pump and pre-filter intake will often be visible too.


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## Mcdaphnia (Dec 16, 2003)

:drooling:


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## RFan (Aug 4, 2014)

Thanks for the advice. I found some old forum posts debating ujs, and it doesn't sound like they are the miracle that the library article suggests they are.

I'm intrigued by the wavemaker/pump idea. A few questions if you don't mind:

1) It sounds like if I try to force the gunk into the canister intakes, I'm unlikely to be successful. And if I am successful, I'm going to have to clean my filters a lot more often or else probably have higher nitrates. Is that right? If so, should I shoot for trying to force the gunk into one small area of the tank to reduce the amount of gravel that needs to be vacuumed? Is that likely to work and save me a lot of time?

2) What powerhead do you recommend for a 6 ft tank attached to a wavemaker? The Super Mag Drive # 2? Would I only need one and where would you place it?

Thanks again.


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## cumbrianewbie (Jul 25, 2013)

I've been having similar thoughts with regards to collecting more of the waste.

I'm not sure about the raising of Nitrates you mentioned. Surely you will have exactly the same amount of waste in your water causing Nitrates, it will just be sat in a different area. That water is continuously being turned over by the filter and air line anyway.

I tried the wavemaker solution. So far however, I have not managed to get the right sized unit. I started with a 1000L/Hour wavemaker. It turns out that was not nearly strong enough for my metre long tank. I then spotted a a 12000L/Hour one on EBay that was a real steal. Turns out that was slight overkill. It started moving substrate, decorations, fish and everything 

It seems I need something in between, but until you test it in your exact tank, it is a little trial and error tbh.

The 1000L/Hour wavemaker is sat in my tank at the moment. It does a great job of collecting all the waste in one corner. Unfortunately it is not strong enough to push it into the filter intake. I will get it right eventually though!!


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## Mcdaphnia (Dec 16, 2003)

I have five Hydor koralia wave makers plugged into one controller. These are more efficient than powerheads. If you have small fish prone to enter the wavemaker when it's off, you might have to screen them off somehow, but I have my wavemakers near the top of the tank pointed slightly downward and so far have not had a problem. Each wavemaker is in a different tank, a 150, two 125's and two 75's. The controller cycles them on and off, creating turbulent flow that flushes detritus out of the rock work and driftwood. At the other end of each tank there is a Poret foam Mattenfilter, and behind that an intake for FX5 cannister filters. A lot of debris does get picked up into the Mattenfilter, and I use a gravel cleaner to siphon out debris from the Mattenfilter.


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## Mcdaphnia (Dec 16, 2003)

This is supposed to be the next new thing, and may out perform existing technology to move detritus around and into a foam pad or sock over a sump or into a canister filter. http://www.saltwateraquarium.com/preord ... -349357237


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## Deeda (Oct 12, 2012)

Now that is a cool new item, the Maxspect Riptide. Not cheap compared to power-heads or circulating pumps but the water movement is awesome. Thanks for posting this!


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## GTZ (Apr 21, 2010)

RFan said:


> I'm considering adding an undergravel jet system to my existing mbuna tank. It's a 6 foot, 125g tank with gravel substrate. I've read the library article on the ujs and done some additional research. But I still have some questions and would greatly appreciate any advice before I commit to this.


What are you using for filtration?
I considered an UGJ system but instead went with an FX5 filter and DIY spraybar, which provides enough current in the tank to keep detritus off the sand. There's no need to vacuum any longer, although I do need to 'rescape' the sand every few months as it tends to shift towards the rear of the tank. The rock work helps to offset this. Anyway, thought this might provide food for thought as a possible alternative.


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## RFan (Aug 4, 2014)

I use 2 Eheim 2217 canisters. How do you have your spray bar and intake positioned?


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## GTZ (Apr 21, 2010)

The spraybar is almost the length of the aquarium, a few inches below the surface, spraying at a slight upward angle. There's also a Koralia 750 on the right blowing towards the intake but it's not nearly as effective as the spraybar.


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