# Oase Biomaster Thermo 600 - Priming problems



## jacquieb (3 Nov 2020)

I was so excited to buy this filter last year! I've always found priming a bit temperamental, to say the least but now I'm really regretting buying this filter: Priming is a nightmare. 

When new it would not start with the existing pre-filters so I bought coarser ones. It grudgingly decided to work, eventually, after many naughty words. 

I tried buying new prefilter sponges, identical to the existing ones but no, she (and it's definitely a she!) wasn't having any of it so I put the old ones back in. That limped us along for a few months but now she won't let me use any prefilters at all.  

I replaced the impeller. I checked all the seals. Filter media is two trays of the coarse sponge, 3 of seachem matrix then the finer sponge on the top level. Pipes are clear and clean.

I dread turning the blooming thing back on - it's always that creaking of doom...what am I doing wrong?


----------



## dw1305 (3 Nov 2020)

Hi all, 


jacquieb said:


> Priming is a nightmare.


I don't know if this thread helps any <"Oase Filtosmart......">. I must admit <"I hate priming buttons"> etc.

cheers Darrel


----------



## Gold Fish (1 Aug 2021)

Hi, 
Do you still have problems with the priming? If yes, I would like to help you. 
I suspect that your problems are coming from the outside of your filter, what I mean is the piping.  Can you describe both sides of the intake and output? Also where is your water level in the tank when you do your priming?
Cheers DG


----------



## Neil6 (1 Aug 2021)

Check your skimmer isn't pulling air down into your filter. Happened to me😂🙄


----------



## Sean Scapes (5 Aug 2021)

Yup biomaster filters airlock very easy. I find that even if you only cleaning the pre filter remove all water from the hoses, I have had to un-airlock the inlet hose and found priming with complete empty hoses works better.


----------



## Wookii (6 Aug 2021)

I always refill the prefilter canister with water when reassembling after cleaning the sponges, which usually means I never need to re-prime the filter. There is usually still a bit of air to purge but its able to get on with it on its own.


----------



## Wesley (3 Sep 2021)

Hello Folk & i'm sorry to possibly be asking a question that has already been answered.
However here we go.
 How do I solve the problem of my Oase 850 taking in Air ?.
I cannot figure out how Or Where the air is getting in. Yet get frequent blasts of micro bubbles.
And
 Will this Damage my filter?
P. S. 
I do not use a skimmer. 
 Thank you.


----------



## Gold Fish (4 Sep 2021)

Wesley, how much watehead you have? 
Can you post a picture of your filter/tank arrangement? The 850 pump is very strong and  it is creating a big suction/pressure difference before and after. Therefore in your canister you may have less then atmospheric pressure and if your gaskets are not licking in air, your dissolved CO2 may fizzle out in gas which you may see. 
Is your filter purge gas out just before your CO2 starts?
I'm looking forward to see if we can solve this mystery.


----------

