Custom Biomaster

[Aqua sobriquet]

When I got my Biomaster 350 I didn’t actually need the large media capacity of the filter, I just wanted the increase in flow over the 250.
Quite some time later I’m now about to fit the original 350 head on a 250 Container and its relevant parts. I’m hoping the reduced height will make maintenance a bit easier as I don’t have a lot of headroom in the cabinet. I’ve seen online that a couple of aquarists have swapped heads/containers so I’m not the only one.

I can’t help thinking that Oase or their retailers are missing a trick here by not offering a build to order option? The 850 for example has a good output but boy the container itself is huge. Another thing I’ve noticed is that the 600 Impeller is different from the 350 but it fits, and works in the 350 head. I’m not sure though if there’s any increase in flow rate?

 

[Bradders]

Quite some time later I’m now about to fit the original 350 head on a 250 Container and its relevant parts. I’m hoping the reduced height will make maintenance a bit easier as I don’t have a lot of headroom in the cabinet. I’ve seen online that a couple of aquarists have swapped heads/containers so I’m not the only one.

The mere 200L flow-through difference by putting the 350 head on the 250 head should not be a problem. You can half that to 100L, so I cannot imagine it's an issue. I remember there was some 'math' that too much flow across bio media can cause issues with bacteria attachment and growth. (I can't remember where I read that now!) But the extra 100 Litres or so I don't expect it to be an issue.

Another thing I’ve noticed is that the 600 Impeller is different from the 350 but it fits, and works in the 350 head. I’m not sure though if there’s any increase in flow rate?

Yes, I have noticed that. And also, the 850 is different in design from the 600. Not sure of the benefits of the design benefits.

 

[hypnogogia]

And also, the 850 is different in design from the 600.

In what way is it different?

 

[MrClockOff]

Tapping in as I'm now in process of gathering all required bits from 250 so I can attach my 850 to it.

 

[Bradders]

In what way is it different?

Just to be clear, I mean the impeller design:

Oase BioMaster 850 Impeller Rotor

Genuine Oase BioMaster 850 Impeller Assembly is a genuine Replacement part for the Oase range of External Aquarium Filters.

urmstonaquatics.com

Oase BioMaster 600 Impeller Rotor

Genuine Oase BioMaster 600 Impeller Assembly is a genuine Replacement part for the Oase range of External Aquarium Filters.

urmstonaquatics.com

 

[MrClockOff]

Btw 850 has more powerful head (more watts) to turn multi van empeller

 

[FrozenShivers]

Could I technically put my 850 head on my 250?...Interesting if so as the 850 is so tall it's a bit of a hassle.

 

[hypnogogia]

Could I technically put my 850 head on my 250?...Interesting if so as the 850 is so tall it's a bit of a hassle.

Yes I think you can.

 

[Bradders]

Technically, you can - as they are all the same fitments.

I did read the below on one website, but I do not know the math behind why this could be the case or the impact. i.e. does this statement only apply to placing a 250 head on an 850 unit?

It is technically possible to combine a stronger pump head with a smaller canister or to reverse it. However, this can have a negative effect on the filtration performance. The manufacturer recommends always using the canister that matches the pump head.

 

[hypnogogia]

I'm not sure why it would make a difference. The speed of flow of the water through the media will be identical, irrespective of which canister is used as the only difference between the canisters is height. So the flow of water using an 850 head will be same speed on an 850 canister as it is on a 250 canister.

 

[MrClockOff]

Technically, you can - as they are all the same fitments.

I did read the below on one website, but I do not know the math behind why this could be the case or the impact. i.e. does this statement only apply to placing a 250 head on an 850 unit?

Not sure about this statement but best thing is that I really don't care as my plants do filtration. All I need is a good flow and maybe some mechanical filtration.

 

[Aqua sobriquet]

I’m not sure if there have been any changes in impeller design but the difference between the 250/350 and the 600 is more noticeable in these pictures.

 

[seedoubleyou]

Just use siporax if concerned about flow. I read somewhere once that siporax likes good flow and to be kept clean.

 

[Aqua sobriquet]

I’m a big fan of Siporax.

 

[Maf 2500]

Are all of the impellers compatible with all of the head units? In other words is the only difference the size, shape and number of the fins? Or is there a difference in the magnets or other factors?

Also, if you buy a new head unit (say an 850) does it come with the impeller or is that an extra purchase?

 

[Bradders]

Are all of the impellers compatible with all of the head units? In other words is the only difference the size, shape and number of the fins? Or is there a difference in the magnets or other factors?

I don't know - but I bet there is a good reason for not fitting an 850 impeller into a 250.

Also, if you buy a new head unit (say an 850) does it come with the impeller or is that an extra purchase?

Any head from Oase comes with the impellor.

 

[Maf 2500]

Any head from Oase comes with the impellor.

Cool, thanks

 

[Aqua sobriquet]

It’s really funny, if you go to the linked site the 850 head is cheaper than the 600 which in turn is cheaper than the 350! 😆

Oase BioMaster External Filter Spares

www.pond-planet.co.uk

I bought a 600 impeller for my 350 just out of curiosity, and because it was quite cheap at the time on Amazon. I only ran it as a quick test and I don’t think there was much if any difference in the flow. I think it was a bit noisier but sometimes these things get quieter over time as the biofilm builds up. It’s this reason that whilst I may remove any obvious detritus from the impeller and housing, I don’t thoroughly clean them like I used to.

 

[Maf 2500]

My concern is that the strength of the magnet in the impeller might need to be matched to the electrical current in the motor/head unit for optimal performance. Not sure if that would be an issue or not...

 

[Aqua sobriquet]

My concern is that the strength of the magnet in the impeller might need to be matched to the electrical current in the motor/head unit for optimal performance. Not sure if that would be an issue or not...

I agree. Impellers are for example different depending on mains frequency. UK and Europe is 50Hz and USA is 60Hz.
Interesting though that the Biomaster 250 and 350 use the same impeller but have different outputs. I’m guessing the Biomaster heads have the same number of plates in the stator but they may vary in size with bigger windings?
This should be apparent by comparing the weight of different model Biomaster heads.
If I remember, next time I clean my 350 I’ll dry off the head thoroughly and weigh it. Perhaps someone with a 600 or 850 could do the same. Whether the scales used have similar accuracy could be a problem though. Best thing would be for someone with two different models to weigh them on the same scales.