Urgent Skimmer is dead and I have no spare ... How long do I have ???

Unless your tank is a super unhealthy environment, it can wait a nice bit of time before you replace it. As said, with the sump, you shouldn't have an issue with gas exchange. Half my tanks have skimmers, half don't. It's not an essential piece of equipment.

 

FWIW, I ran a 75 full reef with 3 tangs for over 2 years with no skimmer. all corals and fish did very well and I had some amazing growth out of the corals.
the tank was 10 yrs old, and I used a DIY Coil denitrator to remove the nitrates.

all fish were very fat and healthy. when I sold the tank when I moved, they all went to happy homes and are all doing well.

 

I've run my tank without a skimmer for about 6 months with no issues. My corals seemed to have had some stunted growth and I had some algae outbreaks, but they were the only visible negatives I could see.

 

If you keep up the water quality you shouldn't see any problems. If you take it off and don't replace it with elbow grease, you may see some algae issues.

 

I ran my 75 gallon display tank for the first year with out a skimmer and am seriously considering taking it back off. So unless as someone stated your tank is seriously nasty already you should be just fine. I never considerer that the algae that was on my glass could be a byproduct of not having a skimmer though, and now it doesn't show up no where near as fast... thats really and interesting fact.

 

i had my protien skimmer off for two weeks (broken pump) and you can see the difference in your fish tank quickly

but everything lived and once i got my pump in the mail every thing is more live again (active)

so two weeks max?

 

Well thanks everyone for the quick responses. I ordered a new Tunze DOC 9210 last night, should be here Wednesday.

I didn't want to go with the same skimmer, considering this one only lasted 18 months ... but its very effective, its reasonably priced, and the space in the sump is built perfectly for this skimmer ... hopefully I have better luck with this one this time around!

 

I agree you would see changes... if you didn't step up the housekeeping and water changes.

Good time to get in some good water changes IMO. I wouldn't wait to for those changes either. Nuisance algae is easy "to get" but rather hard to get rid of.