Hydor Koralia Super-Mod

[smjtkj]

Also, if you mount the propeller furthur up on the shaft as compared to the stock prop, the flow is all directed out of the outlet. It does not flow out of the side at all. Therefore the extra vents are all used for sucking in water. It is really incredible how much flow these pumps produce.

Mike

 

[Horace]

<a href=showthread.php?s=&postid=9372530#post9372530 target=_blank>Originally posted</a> by kroe
I assure you that what I am saying is true, but... I used a MJ 1200 magnet to push the big prop.

I don't think the stock K4 magnet would have a chance at pushing anywhere near as big a prop as a MJ 1200. The stock magnet is puny - seems weaker than a MJ 400 magnet.

I totally buy what your saying, Im not sure you understood my question though. I DO intend on useing MJ1200 impeller on the K4 if I do decide to go with the K4. My only question is what is the biggest prop you can run on the K4 with the MJ1200 impeller?

This will mean I will have to order a couple MJ1200 impellers though. I do have a MJ900 modded with dual nitros...Is the MJ900 Impeller the same as the MJ1200??? If so that means I will only need to order one which would be nice.

 

[chem-e]

The nice part about working with MJ parts is that they're cheap. If the modded-K4 works well, I can by another K4 and an Mj impellor from MJmods for about $10.

 

[smjtkj]

magnet

magnet

The magnet on the 900 and the 1200 are the same. You just break out the center insert and use stiff airline tube for the shaft sleeve. I used a 900 and a 1000 maxijet impeller magnet and they run the same.
Mike

 

[xinumaster]

Do you guys know if the the dry side magnet on the Koralia PH can be place inside the overflow box? Will it not leak some that will be bad for my tank?

 

[smjtkj]

These have to be submersed.

 

[Beenalongtime79]

<a href=showthread.php?s=&postid=9374265#post9374265 target=_blank>Originally posted</a> by dhnguyen
That's not entirely true rufio173.


The MJ mod stream flow pattern depends much on how large the output on the shroud is and how long the shroud is. I used a 1.5" PVC slip coupler for my shroud and it has an ID of about 2 inches. The flow coming out of this MJ mod is very wide and dispursed with a definite cone shaped pattern.


D.

D,

You are absolutely correct. As I stated in my last paragraph, mileage may vary depending on the end user/modder.

I think the Koralia is great for modding. It is so much easier to do than the MJ 1200 mod, as everything is pretty much provided. All you need to do is get the MJ impeller, a prop and some stiff airline and you are good to go.

Cheers,
John H.

 

[Beenalongtime79]

<a href=showthread.php?s=&postid=9375559#post9375559 target=_blank>Originally posted</a> by xinumaster
Do you guys know if the the dry side magnet on the Koralia PH can be place inside the overflow box? Will it not leak some that will be bad for my tank?

The external magnet seems to be well sealed, so I'm guessing you can go ahead and shove the external magnet in your overflow box. I don't think the water will get to the magnet portion.

Actually, the external magnet looks alot like the internal magnet so I think both sides are pretty well sealed.

Cheers,
John H.

 

[smjtkj]

I misunderstood the question about the magnet!

 

[Horace]

So to answer my question from before, do you guys know what the biggest prop you can use with the MJ1200 impeller on the K4 is? I think my buddy tried the dumas 3004 with no luck. He didnt try trimming it any though.

 

[kroe]

Horace - you'll need to experiment some...

I would start with an Octura 1440 or Dumas 3004 and trim them down slightly if needed. That way you'll get the max amount of flow out of them without playing guessing games with props.

I have trimmed down numerous props and they always work just fine... balance of the prop is not as critical as some seem to think (not critical at all IME).

 

[dhnguyen]

<a href=showthread.php?s=&postid=9378266#post9378266 target=_blank>Originally posted</a> by kroe
...
I have trimmed down numerous props and they always work just fine... balance of the prop is not as critical as some seem to think (not critical at all IME).

It is IME if you want it as quiet and with as little vibration as possible.

 

[Horace]

Does the Dumas 3004 move the most out of all props? Last I checked it did, but I am not familiar with the Octura 1440 and others. When I built my MJmod I dont think anyone was using the Octuras yet and the dual nitros were all the rage, I jumped on the bandwagon pretty early . Hell mine still has the soft flex airline holding the rigid airline on lol. Its still working like a champ almost 8 months later though.

 

[filly469075]

has anyone tryed to mod the smaller koralia like k1 or k2 for smaller tanks?
mike

 

[dhnguyen]

The Dumas 3004 is the most reliable large prop to use for modding the MJ1200. The Octura 1440 will put out considerably more flow than the Dumas 3004 but some if not most MJ1200 pumps may not be able to handle it.

 

[slandis3]

a warning for anyone who is useing a k2. A friend of mine had one short out in hs tank after 5 days of use. gave him a bad jolt when he stuck his hand in the sump

 

[Noise]

<a href=showthread.php?s=&postid=9444259#post9444259 target=_blank>Originally posted</a> by slandis3
a warning for anyone who is useing a k2. A friend of mine had one short out in hs tank after 5 days of use. gave him a bad jolt when he stuck his hand in the sump

there is a recall on the K2's and K3's. Some people think the short is the reason. K1 and K4s are supposed to be ok. This is all addressed in another thread.

 

[kroe]

Lots of views on this thread. I did the proof of concept... can someone post pics and details of a polished version of this mod (with a stopper)?

 

[zeusfc]

<a href=showthread.php?s=&postid=9378266#post9378266 target=_blank>Originally posted</a> by kroe
... balance of the prop is not as critical as some seem to think (not critical at all IME).

unbalanced props always cause vibrations... there's a completely different D I Y industry based on this principle!

 

[kroe]

unbalanced props always cause vibrations...

I disagree completely. I am sure a drastically unbalanced prop would matter, but balancing it "by eye" is good enough.

Try it for yourself. Cut down a prop as evenly as you can by eye with scissiors, it will not be any louder or vibrate any more than it did before you cut it down.

I have modified tons of propeller pumps and always go with a prop that is a bit too big and trim it down. The only pumps that vibrate or make noise are those where the hole in the magnet is off center.

It does seem logical that balance of the prop would be very critical, but close is good enough. I think this is due to the high RPMs of the pump. The weight difference of the prop being slightly off is insignificant compared to manufacturing inconsistencies in the magnet (look at how inconsistent the hole in a MJ magnet is... those can't be even close to balanced). Heck... the super glue you use to glue the tube in the magnet probably introduces more weight variation than cutting down the prop.

I think that balancing the weight doesn't matter at all - getting it close is important because you want the two blades to have about the same surface area. Inconsistencies in the amount of water each blade pushes would result in way more vibration and noise than a fraction of a gram difference between each blade.

Please try the exact experiment I suggest before you tell me I am wrong - build a mod, try it, then trim the prop down as evenly as possible by eye, and try it again. Is there more vibration or noise?