# Oase BioMaster 850 flow - not impressed - anything to improve?



## MrClockOff (11 Nov 2021)

Hi all,

I hope everyone is doing well.

Recently I have upgraded my tank to 160L size and connected it to Oase BioMaster 850 Thermo. Filter flow rate is 1550L/H is roughly x10 of tank volume. Filter has connected Yidao CO2 reactor on the outflow. Outflow is original filter's full length spray bar.  
I was aware that CO2 reactor will reduce the flow so I've removed 3 blue sponges from the trays and all original bio media. Bio media replaced with 1L Seachem Matrix divided equally over 3 empty baskets (very thin layer in each basket of 3).

Initially the flow seemed perfect for the size of my tank - all the plants gently swaying and nice ripple at the top of the water. I was cleaning pre-filter once a week but after 3 weeks of using the filter the flow rate dropped significantly.. there is no more ripple at the top of the water despite the level of the water has not been changed.. and plants barely moving.. I have removed 2 remaining sponges from the filter baskets and washed each in the aquarium water also cleaned the pre-filter once again but no change at all.. Not sore what is blocking the flow.. filter is almost empty of media..

I'm looking to find out others experience with using this particular filter and if you could find the way to restore the flow or improve it somehow?

Many thanks,
Dan


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## Hufsa (11 Nov 2021)

Dirty hoses will steal a lot of flow, you dont mention cleaning them? Make sure you also keep the impeller area cleaned


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## erwin123 (11 Nov 2021)

MrClockOff said:


> I was aware that CO2 reactor will reduce the flow so I've removed 3 blue sponges from the trays and all original bio media. Bio media replaced with 1L Seachem Matrix divided equally over 3 empty baskets (very thin layer in each basket of 3).








						Seachem - Matrix
					






					www.seachem.com
				



"Use 250 mL of Matrix™ for each 200 L (50 US gallons) of water.

If I'm reading correctly, you have 1 litre of matrix for a 200l tank. You don't need that much, especially if its a planted tank. Your sponges are also biological media.


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## MrClockOff (11 Nov 2021)

Hufsa said:


> Dirty hoses will steal a lot of flow, you dont mention cleaning them? Make sure you also keep the impeller area cleaned


It's running only just 3 weeks and even has not yet completed cycling. Hoses looking clean to me just got brownish tint no biofilm build up.


erwin123 said:


> Seachem - Matrix
> 
> 
> 
> ...


That's correct I'm using way too much and potentially will remove at least half of it. But the initial flow with that 1L of Matrix was satisfying initially when I just started the filter. I specifically handpicked the largest Matrix stones so they don't block media basket net and thus the flow.

Is there anything what could break like impeller?


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## MrClockOff (23 Nov 2021)

There is one more even more annoying issue with this filter - it’s purging a lot of air..


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## MrClockOff (24 Nov 2021)

Going to try building custom prefilter pipe like in the pimp my filter video


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## Deano3 (26 Nov 2021)

I have the 850 on my aquascaper 900 (180 liters or so) and have a inline co2 diffuser and i purchased a reactor but the flow issue puts me off as no videos showing exact reuction in flow.

I have the red sponge and 1 or 2 blue sponges and 3 trays of seachem matrix the same, to much really but cant harm anything and doubt will change flow very much, i have the aquario lily pipes with the skimmer on the outflow and flow is quite strong as its a jet style and barley get any air in filter now. Maybe its the reactor and spraybar combo and flow just isnt enough,  i know a lot of people complain about the flow on these but i had the 600 and upgraded to the 850 and mine is doing well so far so hope you get sorted 👍


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## Fred13 (26 Nov 2021)

Reactors need a bypass to minimize the loss of water flow as much as possible.
If you do not use a bypass then all the water goes through the reactor which will decrease the flow.


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## MrClockOff (28 Nov 2021)

OK finally I’ve found the solution 
Post in thread 'Oase BioMaster Thermo External Filter'
Oase BioMaster Thermo External Filter


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