Total Power Loss Question

patsheridan · Jan 11, 2017

Just a quick question: In case of total power loss (no air flow, heat, oxygen exchange), how long do I have before things start do die? Specifically, I have a 75g mixed reef, and I live in the SF bay area where the house temp rarely gets below 60, nor above 85.

I am thinking about adding a dummy cell phone to the power outlet for the tank, with an app which would send an auto text to my regular phone in the event of power outage. But realistically, the longest I would be away from the tank is about 10 hours.

I searched for this specific question in the forums without luck.

Thanks!

morpheas · Jan 11, 2017

Without being a chemist (and hating to "evade" the question) I think it's a very fluid thing to make an accurate prediction. It all depends on livestock, bioload, water parameters (CO2 content before, pH etc) but I would say that without any form of gas exchange you don't have but mere hours (1-4 would be my guess for my system anyway). You'd be surprised how easy the O2 depletes from a system with no circulation (I would really like for oxygen measuring probes to become more cheaper and accessible, it would answer a lot of questions that we answer empirically, like me now).

I think your cheapest solution would be a battery powered powerhead pointed at the top. Surprising as it may seem it will buy you exponentially more time than having a completely stagnant system.

Of course, more experienced and qualified people should probably chime in @Randy Holmes-Farley for instance.

JBradford · Jan 11, 2017

While I agree with the suggestion above the part that kills the idea is if he is away from the house for 10 hours and the power goes out at hour 2. A battery power head does no good if you can't turn it on.

I have battery powered bubblers that I can throw in the tank for oxygen if I'm home when the power goes out. That did not give me a great piece of mind due to the if. My advice, which is what I did, get a battery backup for a computer and run your power heads off of that. They don't draw much power and will last a while on a backup, at least long enough for you to get home.

That may be that is what Morpheas was saying and I misunderstood him comment.

AllSignsPointToFish · Jan 11, 2017

I takes a while. For lightly stocked tanks, it can be 4-8 hours before a problem arises. For more heavily stocked tanks, you can run into problems after only an hour or two.

AllSignsPointToFish · Jan 11, 2017

You've got several options for backup power. One option is a computer UPS. Depending on the load, that can buy you an hour or more. You can also buy the battery backup from Ecotech, which will last much longer than a UPS. Either option will automatically transfer when the power goes out. The battery-powered air bubbler is a cheaper option and may be all that you need.

AllSignsPointToFish · Jan 11, 2017

Here is a video that may help:

Brew12 · Jan 11, 2017

patsheridan said:
Just a quick question: In case of total power loss (no air flow, heat, oxygen exchange), how long do I have before things start do die? Specifically, I have a 75g mixed reef, and I live in the SF bay area where the house temp rarely gets below 60, nor above 85.

I am thinking about adding a dummy cell phone to the power outlet for the tank, with an app which would send an auto text to my regular phone in the event of power outage. But realistically, the longest I would be away from the tank is about 10 hours.

I searched for this specific question in the forums without luck.

Thanks!

There are so many possible factors that I don't think you will find a clear answer. The starting point of your tank including DO and temperature will come in to play. Your nutrient levels will come in to play. Is your tank heavily stocked? Did you just feed them?
It is great that you are thinking along these lines though!
Personally, I use MP40's as powerheads. Since they are outside the tank I don't have them on a GFCI circuit which also allows me to run them through a UPS. I will say that the battery backup designed for them does include some nice features that my system doesn't use.

jose7878 · Jan 11, 2017

You can always buy one of those computer back up batteries and plug a power head in which doesn't consume a lot of power. So should give you hrs of run time.

pdt7361 · Jan 11, 2017

There are battery powered air bubblers out there that plug into the wall - the wall plug is so that they can detect with the power goes out and automatically kick on.

pdt7361 · Jan 11, 2017

For me, I use a large APC UPS and just have my 2 power heads connected to it - that gives me 10+hours and then from there I have a neighbor who lets me borrow a generator

brandon429 · Jan 11, 2017

for any tank with potential outages in the prediction, they should be bare bottomed. A sandbed probably commands as much or more oxygen from microbes than the fish bioloading of the whole tank. in the very least its completely wasteful and liable biological oxygen demand from a sandbed. a cleaner sandbed would be less commanding of 02 resources, but most sandbeds have notable detritus stores and bac galore...far past whats needed to nitrify the acting waste sources.

patsheridan · Jan 12, 2017

Thanks for all the great info. I think I will go with a plan to have the phone plugged into the same outlet as the tank, which will then send me a text in case of power outage. This will allow me to get to the house within a couple hours (or get up in the middle of the night), and I would use a couple of battery-operated air pumps to basically blow bubbles into the tank to get oxygen going into the tank. Then (gas stove) heat water into plastic bottles to drop into the tank as needed to keep temps up. Fortunately, living in the SF bay area, rarely do we get an outage that lasts more than 5 or 6 hours.

One other question: how low can tank temps go without causing permanent damage to fish or corals?

v10king · Jan 12, 2017

I would purchase a backup battery for an mp40 or something so that in event of power outage you are covered from a flow perspective. Losing heat will take some time and I Would assume you would have power back on before heat became an issue. IT would be more form an oxygen saturation perspective that you would d have to be worried I would think.

Brew12 · Jan 12, 2017

I would purchase 1 or 2 of these.
http://www.bulkreefsupply.com/silent-air-pump-with-battery-powered-back-up-sab11.html

Very cheap insurance. No installation issue. Should be enough to keep everything going for a few hours.