The "Hitchhiker's Guide" to the Maxi-Stream mod

[GSerg2]

Try it and see is about all that can be said for sure. On a BB SPS tank, you could easily have 35x without a problem.

 

[Critter]

I'm running my 1 MJ Stream 900 dual prop 12 hours during lights on. Then I give the fish etc a break during lights out.

<a href=showthread.php?s=&postid=6573296#post6573296 target=_blank>Originally posted</a> by Jon770
I orderd the dark grey PVC from McMaster-Carr and I'm still waiting for the parts from Tower Hobby...I CAN'T WAIT to make these!

Question: For those who have these in place, do you run them 24/7? If not, how often? How many are in your tank? And what variation of the mod do you have (1 or 2 prop; MJ 400, 900, 1200; etc...)

Thanks for your help.

 

[areze]

2 mj900s with duel 1.25" nitro props. running 24/7 on a 75g.

I wouldnt say its too much flow... Im characterising too much flow as the sand bed not staying down.

if I aim them right of course theyll blow sand, but about 3/4 up in the tank shooting across offset, sand isnt stirred.

 

[Jon770]

What's the benefit to having them on alternating short cycles with timers?

 

[dhnguyen]

<a href=showthread.php?s=&postid=6575392#post6575392 target=_blank>Originally posted</a> by Jon770
What's the benefit to having them on alternating short cycles with timers?

more random flow?

 

[dhnguyen]

<a href=showthread.php?s=&postid=6573668#post6573668 target=_blank>Originally posted</a> by Jon770
ok...but DEFINITELY don't have both running at the same time, right? That would mean I'd have close to 3000gph (x35+ flow)

both of my MJ400's are on in my 55 g all the time. The flow from each pushes against each other to make some really nice turbulence in the tank. Not one dead spot to be seen at all.

 

[GSerg2]

Yeah, the idea is to try to get a more random flow pattern. Ideal for me would be to have both of them going all the time on some sort of rotators that moved them back and forth in about a 45deg arc. Maybe that will be a diy project for me someday.

 

[Jon770]

OK, Thanks.

BTW, I received my dark gray pvc from McMaster-Carr yesterday and it seems VERY thick. I checked the specs you (dhnguyen) posted, and it is the same pvc (I got nervous b/c I ordered 'thick-wall pvc' and thought I made a big mistake). This is the correct pvc, right?

Also, even though about 5 different people each assured me that shpping would only be about $5 to Miami (from their warehouse in Atlanta), my invoice they just sent me lists a shipping charge of $16. I am currently involved in a shouting match with the people over there...I'll keep you posted.

 

[Ball]

I just recieved my PVC and it was very thick as well. I havent measure the inside diameter yet to see what it is.

I also had a lot of problems with shipping from them. My shipping was over $15 and I cancelled my order. They shipped it to me anyway and charged me. I ended up working out that they drop the shipping charges and just charge me the pvc price. They also told me there is no way to show shipping charges before checkout. However, when you submit your order, the charges appear. By then its to late and you have sent in your order. I wont be ordering from them anymore....

 

[ejmeier]

Ha! This is very interesting to come back to this thread after being out of the hobby for over a year. :eek2: I was one of the people from the original thread that was working out the very first bugs in this mod. http://www.reefcentral.com/forums/showthread.php?s=&postid=2599894#post2599894

Looks like its come a long way since then! Nice to see you guys found a suitable shaft. (Great idea.)

Here's some random thoughts/comments I had while getting back up to speed on this mod:

<a href=showthread.php?s=&postid=6521699#post6521699 target=_blank>Originally posted</a> by farrington300
I believe the only flaw to be the stopper wearing down the prop over time. What do you think about eliminating the stopper and allowing the magnet to pull out and correct naturally. Is that too loud, or does it take too long, or does it have to pull out too far. Really what i am asking is there a way to correct the direction of the prop with out uising the "blade hitting something method". any info would be great.

Maybe we could put something on the actual impeller magnet itself to stop/reverse the direction of the spin? Just a tiny little nub, and then another one extending out over the top of the impeller hole that is intergrated into the housing. Just a thought - might reduce stress on the prop and shaft, esp if running constantly on a wavemaker. You never know if doing this over the long term might disrupt that balance of the prop...

<a href=showthread.php?s=&postid=6545423#post6545423 target=_blank>Originally posted</a> by kbmdale
My question is about the life of the power head after the mod. Seems you would drastically shorten the life of the motor by lengthening the shaft and adding bigger props...IMO

The case from the original thread where it was measured that the maxi was using less watts confirms this. Actually, when the pumps are under a greater load, the wattage used DECREASES (sorta seems counterintuitive, doesn't it?) - so the pump was in fact under more stress.

But, IMO, it shouldn't make too big of a difference in the longevity of the pump. The MJ 900 has a max head of 46". In essence, all we are really doing is adding more head pressure (making it work harder.) I've used a MJ as a return pump for a 20g for about a year, and that thing kept running even after its 'tour of duty.' People use MJs all the time in 'feed' applications where they are pumping water from one height to another. Pretty similar to what we are doing here.

 

[taekim78]

Great MOD!!

I have couple of mj1200 and 900's not doing anything that I would like to mod like this. but it seems like it will be way to much for my 29 gallon tank. Is there any thing I can do to take down the flow a bit, let say aound 800GPH? less slot or holes cut in to the pvc pipe maybe? is there a differnt prop. I can get to lower the flow?
( going BB and dont want to shell out more $ for seios)

thanks for your help guys!

Tae

 

[twilson2003]

Could possibly just use a little smaller propeller...Or just trim one down to say 1" or .75"....Just a thought....

 

[Jon770]

I think less slots should also reduce flow...

Less In = Less Out

 

[areze]

smaller propellor, dont cut the prop though, it would probably throw off the balance, and the dynamics of it.

or drill a few slots in front of the prop, some of the flow will disperse out of it.

 

[dhnguyen]

for a 29g use MJ400 or MJ600 and either 1.25" or 1" Dumas prop

 

[taekim78]

Don't want to shell out more $ for MJ 400 or 600. got a lot of 1200 and 900 doing nothing from my prev. tanks. Let me try with the smaller prop and I'll update you guys

 

[areze]

the MJ size doesnt matter, except in wattage maybe.

their all the same RPM I think, so the prop is the difference.

 

[dhnguyen]

That's not really true areze. The MJ400 I know for a fact is not strong enough to spin 2 props. So the torque is also very important.

D.

 

[areze]

ok true. but assuming equal props, and them being able to spin them. and he wanted to use the 900 and 1200s. which would make no difference in having more flow than a 400. maybe a tiny difference if the 400 was slowed down, but with a small prop their all probably within 50gph of each other.

 

[douggiestyle]

that ecotech thing is cool im assuming there are no holes in the glass.

how bout this for a mod. figuer out a way to mount this mj mod thru a bulk head. so that the motor is on the outside of the tank.

yes i see some problems with this but thats whats problems are for, solving.