need help with under gravel jets

[Bigougit]

So I've been planing to order a Rio 2100 along with some sand for my malawi tank, but I found out my LFS was going out of business and selling things extra cheap. So, instead of getting a Rio I ended up getting a Maxi-Jet 900. It was the most powerful submersible pump they had so I thought "okay, why not?".

My question is, will the maxi-jet 900 be powerful enough for under gravel jets. They're purpose is to create current in the tank and supposedly make it so you never have to gravel syphon by using a water pump hooked up to pvc pipe. The rio pump that was recommended to use is rated at over 600 GPH and my Maxi-Jet is at 230 GPH. Me and my wallet have been arguing over this one, I would like to just go get the Rio 2100 anyway but that costs more money and I cant return the other pump since my LFS was moving. So, will this work?

 

[Bigougit]

got some help on another forum, a guy said it would work for water movement, but I'd still have to do some gravel syphoning. I guess thats better than nothing though

 

[mp3z24]

the maxijet pumps are not rated for a large pressure drop. so, you cant use them to pump a large amount of water through a pipe. depending on the amount of piping you are going to use and the number of bends you are going to use, it MIGHT work. also, the outlet of a maxijet pump is not good for attaching to pipe. if you do use it, try to use 45 degree bends instead of 90 degree bends, and use a pipe that is 1 or 2 pipe sizes larger than the outlet connection of the pump (i.e. if the pump outlet is 1/2 inch, then use 3/4 inch or 1 inch piping with a pipe reducer).

basically, the pump can only do a certain amount of work. anytime you use a pump, there is an automatic balance between the amount of water pumped, and the pressure generated by the pump.

when the maxijets are used as water circulating powerheads, there is basically no pressure for them to push against, so they have a large flowrate. there is no pressure, because they are not working against gravity or against friction.

if you try to use a maxijet to push water thorugh a pipe, you are adding friction. so, the pump will move less water because it now has to provide some pressure to overcome the friction. the same concept applies if you use a pump to move water up against gravity. the pump will have a lower flowrate because you are increasing the pumps outlet pressure to overcome gravity.

hope that makes sense.

~mike

 

[Bigougit]

Yeah, it makes sense and is somewhat devastating at the same time. I went to home depot today with my mom to help her pick out a weed eater and she suggest using smaller pipe so that it would have to work harder to get through it, it sounded good at the time but considering what you stated I'll probably have to return the pipes tomorrow for something bigger (I have 5/8'' pipes).

I did however order a second pump today, its another Maxi Jet 900 so that I could use the same method of attachment.

Thanks for the advice

 

[mp3z24]

i think the maxijet pumps can be connected to 5/8 tubing. after that, you should increase your piping to at least 3/4 inch... if not 1 inch. what your trying to do *will* work, but i dont think it will work as well as you want it to.

if i were you, i would use the powerheads that you have purchased as in-tank circulation pumps, and look at a mag-drive pump, or some other type of submersible water pump... not a powerhead. circulation power heads are designed to work with minimal discharge pressure. water pumps are going to have better capabilities for the application you are talking about.

~mike

 

[Bigougit]

I ended up using 1/2'' tubing. I found a peace that fit screwed into threaded pieces and held the pumps perfectly secure, but it swivels around (I can use the suction cups that came with it).

I couldn't Imagine using bigger tubing in a 55g tank though, I used all 45 degree and Tee fittings instead of corners and it should leave hopefully enough space to ease it all into the tank. I guess I kind of screwed myself by impulse buying the powerhead while it was so cheap. If the pumps create current at all I'll be happy lol

I'm hoping that this will just help make the fish feel more "at home" and in a 55g putting in allot of current might turn out disastrous. My girlfriend almost had a heart attack when I tested the powerhead oh my asian tank, plants on the opposite corner of the tank were moving from the current lol (was hoping to build some bacteria in the sponge).

Anyways, I'll be happy if the pumps work well enough so that I can limit gravel syphoning down to a bi-weekly or monthly chore.

Thanks for all your help!

 

[Bigougit]

Well, my tank's all set up and aside from one of my jets being alot stronger than the others the system works great. It may not prevent gravel syphoning, but it should decrease them. Using the 2 weaker pumps was probably a mistake in the long run but they were ALOT easier to install lol Hopefuly the fish will like the jets too, thanks again for everyones help

 

[malkore]

UGF doesn't work well with sand. If you decide to go this route I would suggest a reverse UGF.

 

[Bigougit]

UGF doesn't work well with sand. If you decide to go this route I would suggest a reverse UGF.

I was never considering a UGF, I have under gravel jets, it uses PVC pipe hooked to a pump or power head to create current in a tank