# How noisy should a biomaster thermo 250 be?



## DaveWatkin (15 Nov 2021)

As per the title. Fitted one yesterday and it has a low hum, like a PC tower with fans going. 

Not bad but I’ve read everywhere how quiet they are supposed to be so want to make sure it’s not faulty. 

It’s the unit itself as when I lift it there is no change to the noise, hoses are also free and not touching the cabinet.

Is it normal? Couldn’t even tell if the ehiem it is replacing was on without looking at the water.


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## SRP3006 (15 Nov 2021)

I'll start by saying I like my oase biomaster 600, (owned a 250 and it was similar in noise levels) but they are up there with the noisiest filters I've owned, I would go as far as saying it is noisier than my fluval fx6. Which is a shame as they are good reliable filters and the prefilter is a god send for someone like me that doesn't like opening the filter 😉 
There are several threads on this forum complaining about their noise levels.


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## Djoko Sauza (15 Nov 2021)

Mine was quite noisy, it rests now on a thick foam pad and is much quieter, I'd give that a try if I were you.


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## Angus (15 Nov 2021)

Foam pad like diogo said, also try unplugging it and plugging it in a few times and gentle shaking to clear any air locks in the impellor, almost every brand of filter i have had has had noise problems due to cavitation and when you get the impellor sorted they quieten right down, Eheim, Tetratec, JBL, fluval etc for example.


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## SRP3006 (16 Nov 2021)

I've tried the foam/insulating cabinet, however I still get moaned at about the loud humming noise. I'd switch filters but not sure what my alternatives are really.


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## Courtneybst (16 Nov 2021)

My Biomaster 350 is pretty quiet, can't hear it at all. My 850s on the other hand are very noisy. Can hear the hum from upstairs at night, and I've tried the usual things.


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## Geoffrey Rea (16 Nov 2021)

If your piping rests on the cabinet at all it can transfer vibration. That is common. As @Diogo Sousa has mentioned, a slice of foam underneath the filter will quieten the unit down in general. It is also worth checking if the rubber pads on the base are present.

Will put it out there that running an Oase filter on anything other than 100% flow, with the tap fully open on the cassette, is involved in many problems with these filters. Estimate the pressure created overcomes the seals and you get the commonly reported leaks and ingress of air without an obvious source. Put some faith in this theory as have advised a few folks with issues to run their filter on full and it stopped all issues. If ran with the flow fully open, they’re commonly trouble free.

People don’t report filters that are working, just when they don’t. There is always the potential for manufacturing issues with specific filters though.

The low hum beyond all these issues can sometimes disappear. Suspect a biofilm builds up on the shaft of the prop and lubricates it. You can try silicone grease on the shaft to remove friction.

Also this:



Angus said:


> try unplugging it and plugging it in a few times and gentle shaking to clear any air locks in the impellor, almost every brand of filter i have had has had noise problems due to cavitation and when you get the impellor sorted they quieten right down, Eheim, Tetratec, JBL, fluval etc for example.





SRP3006 said:


> I'd switch filters but not sure what my alternatives are really.



Even the new Eheim 5 series is noisy. It’s almost like we’re going backwards with filter tech.


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## Angus (16 Nov 2021)

Geoffrey Rea said:


> It’s almost like we’re going backwards with filter tech.


Business opportunity for noise cancelled filter range me thinks, any business reps reading?


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## Geoffrey Rea (16 Nov 2021)

Angus said:


> Business opportunity for noise cancelled filter range me thinks, any business reps reading?


 
Less marketing, more engineering!!!

Don’t need Wi-Fi connectivity on a filter. Just needs to be invisible and silent… like they were 20 years ago 😂


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## CooKieS (16 Nov 2021)

Hi there,

I had two biomaster 600 thermo , worst humming noise I have ever encountered coming from an external filter. Returned the first one, got an second one that ‘should be better’ (oase team), same.

Flow wasn’t especially good either. Prefilter cleaning option, thermo, and plastic quality were very fine but… Back to eheim and Aquael.

At this price I think oase could go with an ceramic axle rotor to avoid this annoying bassy humming noise…?


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## CooKieS (16 Nov 2021)

Geoffrey Rea said:


> Less marketing, more engineering!!!
> 
> Don’t need Wi-Fi connectivity on a filter. Just needs to be invisible and silent… like they were 20 years ago 😂



This…and sturdy plastic again please. 😁


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## Geoffrey Rea (16 Nov 2021)

CooKieS said:


> This…and sturdy plastic again please. 😁



… And the red rubber seals that don’t perish…

(You know we’re describing the old Eheim filters right…?)

😂 😂 😂 

Whilst we’re at it… And free beer with every purchase 🍻


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## Courtneybst (16 Nov 2021)

Geoffrey Rea said:


> … And the red rubber seals that don’t perish…
> 
> (You know we’re describing the old Eheim filters right…?)
> 
> ...


I'm almost regretting selling my old Eheim 2217. That thing ran for 11 years without ever changing any seals, no lubrication and only cleaned the impeller 3 times during the 11 years. Thing worked like a charm and was powerful AF for the price. I suspect if I bought an Eheim 2217 now it would be flimsy?


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## Geoffrey Rea (17 Nov 2021)

Courtneybst said:


> I'm almost regretting selling my old Eheim 2217. That thing ran for 11 years without ever changing any seals, no lubrication and only cleaned the impeller 3 times during the 11 years. Thing worked like a charm and was powerful AF for the price. I suspect if I bought an Eheim 2217 now it would be flimsy?



The original Eheim Classic 600 was so good that ADA found some very talented welders, then made it out of stainless steel and charged four times the price. Granted, the pump on the Superjet is designed to be inherited.


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## jaypeecee (17 Nov 2021)

Hi @DaveWatkin

You may also get some ideas from the following thread:






						Most quiet external filter
					

Hi All, I have 2 large aquariums, both around 450 litres. Both currently have FX6s filters with a U4 internal in one and a built in juwel internal in the other.   The FX6s are just too noisy for my liking, I have tried everything, new impellers, shafts, sitting it on sound proof foam and sound...



					www.ukaps.org
				




JPC


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## lazybones51 (17 Nov 2021)

Courtneybst said:


> I'm almost regretting selling my old Eheim 2217. That thing ran for 11 years without ever changing any seals, no lubrication and only cleaned the impeller 3 times during the 11 years. Thing worked like a charm and was powerful AF for the price. I suspect if I bought an Eheim 2217 now it would be flimsy?


The 2217 I bought a couple of years ago was really noisy, even when on a foam pad! No amount of changing impellers/shafts or shaking it to dislodge air made any difference. I replaced it in the end with a custom setup using a marine pump, water filter and hard plumbing.


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## dw1305 (17 Nov 2021)

Hi all,


Geoffrey Rea said:


> Less marketing, more engineering!!!
> 
> Don’t need Wi-Fi connectivity on a filter. Just needs to be invisible and silent…


_Hallehujah, hallelujah, hallelujaaah_!

That is it, same for me, I want <"the coffee, not the froth">.

I'm in if any-one wants to produce one? But we have to call it the <"pump in a bucket by _Luddite_">. I've got ideas <"for pricing">  and
<"advertising as well">.


dw1305 said:


> ..............  only ever picked up by a one-legged ginger Irish-man ............



cheers Darrel


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## hypnogogia (17 Nov 2021)

Geoffrey Rea said:


> Less marketing, more engineering!!!
> 
> Don’t need Wi-Fi connectivity on a filter. Just needs to be invisible and silent… like they were 20 years ago 😂


Indeed, WiFi connectivity is a nonsense, but have they really become louder, or are we just using more powerful and therefore louder filters because we want 10X flow?


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## Angus (17 Nov 2021)

hypnogogia said:


> Indeed, WiFi connectivity is a nonsense, but have they really become louder, or are we just using more powerful and therefore louder filters because we want 10X flow?


With great power comes great responsibility to add rubberized and isolated parts.


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## arcturus (4 Dec 2021)

DaveWatkin said:


> As per the title. Fitted one yesterday and it has a low hum, like a PC tower with fans going.
> 
> Not bad but I’ve read everywhere how quiet they are supposed to be so want to make sure it’s not faulty.
> 
> ...



Not sure what type of noise you are experiencing. In any case, be aware that you can improve the performance of the Oase BioMaster if you replace the existing pre-filter pipe with a drilled PVC pipe with 20-21 mm inner diameter. The existing pipe has a diameter of ~15mm and an small number of holes. A larger pipe will increase the flow and also reduce the overall operating noise of the pump. Even if this does not reduce the noise as much as you wish, you will at least benefit from the additional flow. Here is a video showing the procedure.


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## H.Alves (4 Dec 2021)

I think it was proven already that drilling more holes/ increase pipe size does not improve flow, at least, if the sponges are clean.


Enviado do meu iPhone usando o Tapatalk


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