Built an Under Gravel Jet system

[Luca Brazzi]

This was a pretty simple project. I used a Rio 1700 submersible pump (since its only being used to move water around the tank Im not really worried about Rio reliablity). Anyway, the Rio comes with a 3/4" threaded attachment which I connected to a 3/4" threaded to 1/2" slip fit elbow. This elbow connects to another elbow which feeds the 1/2" lines for the jets. The jets are attached to the undergravel plumbing using 45 deg elbows, and each jet was made by heating up a short piece of PVC with a heat gun and pinching one end with a pair of pliers. I found that I needed to pinch the jets closer to the pump closed more to get an even flow from all the jets. I orignaly got this idea from http://www.vatoelvis.com/ in the articles section. It should be a good way to keep debris off the bottom of the tank. http://www.vatoelvis.com/ specifies 3 jets per pump, I used 5 jets which means that the total pressure out of each jet will be less but how much force does it take to lift a piece of fish crap? I could see if I had a shark or something. Anyway, if I find that the pressure isnt great enough, I can always stack a second pump on top of the 1st and feed it into the same plumbing or just get a bigger pump.

[superstein61]

Luca

I pretty much did the same thing. I used the concept from www.vatoelvis.com but instead of using the Rio pump and PVC - I used a fully submersible Maxi-Jet 1200 - and some clear vinyl tubing and some plastic connectors / nozzles I found dirt cheap at my local hardware store. It seems to create some nice flow / circulation on the bottom of the tank. My tank is still cylcing - so I have yet to see how the fish will react - but its nice to see some plants "swaying in the breeze" - LOL

[Luca Brazzi]

Whats the GPH on the pump? How many jets did you use? Is the flow for each jet adjustable? How far up do your jets shoot if they were not submersed? I angled my jets to push the water around the tank kind of creating a whirlpool effect. Im hoping that any doodoo will be swept around to be caught by the overflow. I also plan on using a bubblewand along the back of the tank to create an upward flow there. Did you Aquascape before you did the jets or did you do the jet system and the aquascaping together?

[superstein61]

Luca - I believe the GPH on the MaxiJet is 295 gph. I used 3 jets but did not make the flow on each one adjustable. The vinyl tubing and jets are fully submersed under my gravel - with just the tip of the jets sticking out. Hard to say how far they shoot up - I didn't really measure it.

I too laid out my jets - but in a fashion to drive water / detris from right to left (because on the left side, I have a built in overflow to my filter - so I wanted all the gunk headed that way.

I also created a fake rock wall (out of styrofoam, sand, and epoxy) - and put a bubblewand behind a crevice to create upward flow. I basically installed my system and aquascaped at the same time

[karfixer]

superstein61-That sounds really interesting-Any pics?

[Matak]

Luca, is this a reverse flow or regular type undergravel filter?

[Luca Brazzi]

Matak...

It is neither. Its not a filter.

Its basically like a fish Jacuzzi. There is a pump, connected to PVC pipe that is hidden under the gravel. There are several outlets to the PVC where there are "jets" (basically the jets are pinched PVC pipes), that shoot water upwards creating an upward current which keeps debris off the substrate.

[superstein61]

karfixer

I haven't taken photo's yet - but plan to do so as soon as I have some free time. When I do, I will post them.

Not sure if you are asking about pics of my water movement tubes / etc - or my fake rock wall. If its water movement - continue on. If its the rock wall - I hopefully will get some up here by the end of the week.

On the water movement, you can get a good idea of the concept by reading this article and checking out these pics (which is what inspired me and Luca both to do this)

http://www.vatoelvis.com/Movement.html

The section near the end of the article - and the last 4 pics are what you want. This site, like Luca used PVC and a Rio pump. The biggest difference for me was I used a fully submersed (hidden behind driftwood) Maxi-Jet 1200 Powerhead - and clear flexable tubing - with plastic connections. I Initially planned to use the PVC - but upon getting it home, didn't like how large it was and was worried about my gravel covering it - and eventually becoming uncovered. So I decided to take the pvc back to Home Depot and go with the flex tubing (same stuff that you would use outside the tank if connecting a pump from a sump or cannister back to your tank). This has worked quite well for me.

[Matak]

Well, I suppose if I had actually read the article I would have better understood.

It looks to be very functional. I have a planted tank and water circulation is a tricky subject. You want to circulate enough to get rid of dead spots, but not so much that you disturb the water surface and therefore lose valuable CO2. This looks like a good and cost effective (read cheap) solution.

[Luca Brazzi]

superstein61,

You mentioned that you were concerned that your substrate might not cover the PVC. What sized PVC were you using? Im using 1/2".

[karfixer]

superstein61, I was thinking about the rock wall :cool:
The water jet idea seems really neat-I'm think maybe to use it as a return for a wet/dry sump-in part anyway. Thanks for all the great ideas everone :D there is a lot of creativity around here. Happy New Year, Steve

[superstein61]

Luca - yes, I was going to use 1/2" PVC - but whn I started looking at it - especially at the elbows and T connectors I was having, I had some concerns.

They were probably overblown however as I am sure my substrate would have covered the PVC. However, I just felt more comfortable going with the flex vinyl tubing instead as the 3/8" diameter tube I used was about half as high as the PVC at the connections (due to the thickness of the PVC pipe and the diameter measurement being the inside measurement.

[superstein61]

Karfixer - I will try and get some pics up of my rock wall and how I did it in the next week or so. Its a fun project and yields great results IMO

[Luca Brazzi]

Ive been testing out the undergravel jet system in my empty 75 gallon tank. It seems as if when the jets are on they tend to disturb the normal flow of debris to the overflow and drain. I dont know if this will be a problem or not. Maybe I can orient the jets so that they dont have any affect on this.

[superstein61]

Luca

Try readjusting the jet angle to cut down on thw whirlpool effect you have.

This is why I have by jets just flowing from right to left (my overflow is on the far left). The current thus all flows right to the overflow

[Luca Brazzi]

I have an overflow in the back left corner. My return comes out of the overflow box and has an elbow on it that is currently pointing straight down because a return jet that blasts outward was affecting flow of debris to the overflow box. I have one jet angled to the right in the middle-back of the tank, one in the right-back corner pointing towards the front-right, one in the front-right pointing towards the left, one in the front-middle pointing left, then one in the middle-left pointing towards the front. I think that all of these except for the last would tend to create a whirlpool around the tank going from the back left towards the right, then around the front and back to the left. I think youre right... I need to readjust the jets so that they all just point to the overflow.


What to you use to agitate the surface for oxygen replenishment? I could probably route the return to do this, but it would also disturb the flow towards the overflow unless I route the return to the opposite side of the tank (using 1/2" PVC or something).

[125gJoe]

If I had fish that loved rather fast moving water, I'd try the fish "jacuzzi"! I saw it some months back and really liked that idea on keeping the water moving. It sould be good on many saltwater tanks too..

http://www.vatoelvis.com/Movement.html

[superstein61]

Karfixer - ok, you can go here to see my rock wall:

http://www.speakeasy.org/~jfd61/fish/fish3.htm

[karfixer]

Thanks - that looks excellent, nice web page too.

[Luca Brazzi]

Well I finished the jet system and it is now hidden nicely underneath my Black Beauty substrate. I did have an issue however since the PVC, jets were white, they stuck out like a sore thumb so I simply coated them with silicone, and shook them in a bag full of the black beauty. Now you can barely see them.

[125gJoe]

Originally posted by Luca Brazzi
.....the PVC, jets were white, they stuck out like a sore thumb so I simply coated them with silicone, and shook them in a bag full of the black beauty. Now you can barely see them. Wow! Excellent idea!

[superstein61]

Luca, are you going to post any pics?

[Luca Brazzi]

I hope to post pics after I get Aquascaped, etc.

[superstein61]

Luca, ok sounds good.

just one more question - what are you gonna do when you run out of things to build ? LOL

just read your sump thread - sound nice

[Luca Brazzi]

When I run out of things to build?

Hmmmmm... Lemme see....

Maybe Ill get a fish or two :D

Actually my next feat of DIY (other than building a much bigger tank of course) may be to monitor/automate certain things in the tank... Ive got 18 years experience in software design and electronics, and Ive been seriously eyeing some of the stuff at http://www.automatedaquariums.com/ Specifically Im interested in, Water level control/monitoring, flow monitoring, and dosing. My tank is in a position where its only one hole in the wall away from a water source and drain in an adjoining bathroom... maybe I can automate water changes and evaporation replacement, etc.

The fish are secondary to me actually (dont get me wrong... theyre great pets and I dig watching their behaviour, etc. but...). For me live, healthy fish will simply be the fruit of good system design...

[superstein61]

Originally posted by Luca Brazzi


The fish are secondary to me actually (dont get me wrong... theyre great pets and I dig watching their behaviour, etc. but...). For me live, healthy fish will simply be the fruit of good system design...

LOL- I could tell you really enjoy this DIY stuff. Thats great.

Actually I do recall reading some DIY plans on the web for automatic water changers/ monitors, but I can't recall where. They did sound very interesting if you had the right place for them (I do not). Have fun, I am sure you will design something good

[musket3]

Hello all. I am new to the forum and was wondering if anyone has built an under gravel jet system with random holes drilled into the PVC tubing, similar to a an Eheim spray bar, instead of just a few jets. I am talking about the PVC buried in the gravel the same as the UGJ, not near the surface of the tank. I built one yesterday but am not sure what size holes to drill, I don't want too much pressure or too little either. I took the assembly outside and connected it to a garden hose and got what would be probably too much flow for the fish. It would be great if it would fit in the bathtub but my tank is a 125 gallon and the assembly is too long. The faucet outside is far different from the flow from my pump so that probably wasn't a good test. I found a number 29 drill bit, 0.136 inch, to be a perfict fit in my Eheim spray bar so I drilled about 40 holes with a number 46 bit which is 0.081 inch. My reasoning is that the Eheim spray bar only has 9 holes so I went with a much smaller drill bit so tht I could drill holes ever 4-6 inches in the PVC. I built this to go around the perimiter of the tank with 2 tees and 2 short sections of pipe front to back. The pump is a Rio 2100+ which, according to the box is 692 gph. I don't want this to be a trial and error affair because my fish are in the tank and I don't want to scare them any more than necessary. Does anyone have any ideas or experience with this? Thanks.:help:

[Phatboydime]

Musket, Im pretty sure it would take alot of some type of math Im not good at to figure out an answer to your question on paper. You could always use my method, just do it, and see what happens.

Drop it in the tank, cover it with substrate, adn turn it on...see what happens.

That said. Im interested in your findings, as I had the same idea.

[musket3]

I decided to start another tank, a 40 gallon breeder, 36x18x16 inches. I cut the pipes to fit and it seems to be working fine, not too much water movement, so it shouldn't bother the fish. I am waiting for it to cycle so I can get some fish for it. The pump is a little loud so I expect to get another brand but not sure what to get.

[Veloth]

Musket3 this might help with what you're trying to do.http://www.plantedtank.net/forums/diy/78505-rfug-blast-past-diy.html