Going Away for 8 Days - Should I turn off sump

[Sk8r]

Your skimmer provides significant oxygen. Without circulation it can't reach your tank. You might try installing an airpump with considerable push to aerate your tank directly, but the bubbles mustn't touch specimens or fish. You will also have evaporation, which will concentrate salt and raise salinity. I'd estimate under normal circumstances, you'll lose about half a gallon to 3/4 gallon of water a day, meaning about 6 gallons down. When you come back your salinity will be that much higher, maybe about 13% too high? Check my math. So when you come back have some ro/di ready to add to your system, slowly bringing the salinity back down, spread over the next 12 hours. I'm a terrible mathematician---so do work it out independently, but it should stay within tolerance except for fragile specimens, and AFTER this, get an ato and learn to use it. Doing it wrong can work a sudden salinity change which would be worse than the prospect of leaving for 8 days. Slow can be tolerated much better than fast.

If you CAN get someone to come in, make a taped 'fill line' on your tank and tell the sitter just to pour 'this pitcher' into the tank until the water is at 'that' line and don't dare hit the light kit while pouring.

 

[BrianKC]

Let me preface by saying that Sk8r and others advice is the right answer; you should keep all your equipment running and have someone come top off for you. That is best because it's a system that works for you and a working known quantity is better than an unknown. Not to mention the inevitable hyper-salinization of your tank. Others have already posted the maths that show even if you started slightly hypo-, you'd come home (in my opinion) unacceptably hyper-salinated.

That said; the chemistry/physics of alternatives bears some debate...speaking only of oxygenation, the bulk of oxygenation comes from surface exchange. Your real goal is to get water from the bottom of your DT to the top, along with good surface agitation. Bubble walls, air stones, etc would be enough for a smaller bioload, but your better bet is a pair of powerheads on opposite ends of the tank. Mount one just below the surface pointed slightly up/across the tank pointed at the other end to make a lot of surface ripples. On the opposite end, mount the other near the bottom, aimed slightly diagonally up towards the other end (the end with the first powerhead). In this way, you'll create a horizontal vortex that will constantly move bottom water up and across the surface to exchange fresh air into the water.

The downside to a lot of surface agitation is more evaporation, so it's really a catch 22. This is better advice for how to deal with a temporary power outage and keeping the tank oxygenated with a small battery backup than going away for 8 days. You should really try to get someone to pop in a few times to top off. Even every 3 days would be okay (not ideal, but better than turning off your skimmer and letting 8 days of evap go).

 

[moneymm]

I don't see a problem with it, unless maybe you're sps dominated. I have mostly softies and lps, and currently running a sumpless 75g for two years without a ato. I've took way longer than 8 days to top off the tank, even turned off the skimmer for a month or two. Just as long as you have surface agitation from the powerheads, auto feeder, and a heater in the DT you should be fine.

thanks. i dont have any corals

 

[thelawnwrangler]

moneymm enjoy trip and good luck with tank

 

[Itchy fishy]

Prob about the best purchase was me ATO, I wasn't with the smart system. My nano cube only went through about a 1/4 gal a day and thought it was no big deal to just top off everyday. The ATO was super easy to set up and never regretted the buy.

 

[LefkoNJ]

Plan for coming back though to drain that sump completely and the skimmer to be very busy. I agree with the ATO suggestion but you may be so close to your departure date that you won't feel comfortable having that new piece running while you are away.