90 gallon- power outage question

[Martini5788]

I am getting a 90 gallon aqeoun next week, and I am curious in case of a power outage how much water will drain into the sump? Gallons wise? I'm trying to figure out how much space to leave in my sump in case of an emergency

 

[Jade5051]

Depends how your return line and overflows are designed. Most likely there won't be more than 3-5 gallons. Check valves will stop the return line from starting a siphon which will drastically reduce the amount returned to the sump.

 

[MrCaveman]

Check out the sump volume calculator on the home page of RC. I always use the extreme case 2" above overflow and never had a problem when sizing my sump

 

[MrCaveman]

I don't rely on check valves as they may eventually not seal 100% after its been exposed to salt water for some time, Ive used two check valves on two different tanks and they always had a little dribble still going into the sump when the pump is off

http://reefcentral.com/forums/showthread.php?t=2520510&highlight=siphon+break check this out too

 

[Martini5788]

I always use tapatalk, that's probably why I have never seen that haha. The only standard size tank I can fit in my stand is a 20 long. Hopefully that will be okay. I'll definitely put a check valve on it though.

 

[Sk8r]

I've always used the pull the plug method, with a friend. YOu pull the plug and have a friend stand by to plug it in when you scream "Plug it in!"
Then you take out a gallon or so and try again.

As a rule of thumb, your sump should be about 2/3rds full while running, and you should have a couple of inches to spare between water and rim when it's in 'off' mode. So remove water down to about 2/3 of the sump during operation and that should be close.

But if your sump is way too small this might not work. I use a 30 gallon sump on a 105 gallon tank.

 

[Martini5788]

I am going to use a 20 gallon long for the sump. The calculator said 7.5 gallons.

 

[davehead86]

I am going to use a 20 gallon long for the sump. The calculator said 7.5 gallons.

Not big enough for a 90 gallon. Sorry. 30 would be minimum, bigger is better though. Id do a 40.

 

[Martini5788]

Well I can't use either a 29 or a 40. They won't fit
In my stand. The 29 is
Too tall, I wouldn't be able to remove any equipment from it or do any
Maintenance. So those are out of the question. Why do you
Say it's too small?

 

[davehead86]

Well I can't use either a 29 or a 40. They won't fit
In my stand. The 29 is
Too tall, I wouldn't be able to remove any equipment from it or do any
Maintenance. So those are out of the question. Why do you
Say it's too small?

Because you need to have 7.5 gallons of overflow incase the power goes out, that leaves you with 12.5 gallons in a 20 Long tank, thats not very much water at the bottom for the skimmer and return pump to operate. If they both can operate then your fine, but it just seems like its too little water IMHO.

You could make a custom acrylic sump. From what I have read it seems like a simple straight forward process after you practice on a few pieces.

 

[Martini5788]

I'm not making s custom acrylic sump. What is confusing to me is that sump manufacturers rate sumps with the same overall
Volume for tanks up 120 gallons.

 

[davehead86]

I'm not making s custom acrylic sump. What is confusing to me is that sump manufacturers rate sumps with the same overall
Volume for tanks up 120 gallons.

im just telling you my opinion. Seriously, if you can get your skimmer and return pump to work then its all good. I personally think its a little bit on the low end, but it could very well work out.

 

[Martini5788]

im just telling you my opinion. Seriously, if you can get your skimmer and return pump to work then its all good. I personally think its a little bit on the low end, but it could very well work out.

There are a lot of baffles in it, everything is in a different level so hopefully it will be fine. I may end up putting the 20 gallon inside a Tupperware container, so if it overflows it won't get on the floor. A larger sump just isn't an option though, won't fit.

 

[Texas Paul]

Tip: drill a small hole in the return line inside the tank. Start with the smallest you can get by with. It will break the siphon quickly in a power outage. It needs to be at or slightly below the water line. It can be in the internal overflow box above the water line if the returns are coming up that. If the hole doesn't break the siphon quickly make the hole the next size larger. I would think 20 gal is fine. Good luck!

 

[DavidGraves]

How do you have the sump setup? Skimmer, return, fuge?

 

[ucdcrew]

I was running my 100 with a 20L before i upgraded my sump. I had no siphon break, mine just drops down to the point where the water stops sucking in the input.