Battery Backup Air Pumps: Best Practices

[FishyIdea]

Earlier we had a thread on siphoning dangers with these--something I had not thought of, so I have added airline checkvalves to my shopping list. Thanks for the tip!

Here's what I intend to do with mine. I have a 90g with a 30g sump and a small fuge in the sump. I have three of these pumps. Place one to serve the fuge. Place two to be hidden in the corners of the display.

Questions:

What is the best choice of airstone or plastic diffuser for saltwater? By "best" I mean the one that can go the longest without needing maintenance or replacement.

What is the maintenance or replacement regime for these air diffuser devices that sit idley in your tank?

Has anyone looked into good rechargeable batteries that you can swapout once a month. Otherwise, what is the best replacement strategy for disposable batteries? Once a year like smoke alarms?

Joe

 

[starrfish]

Joe, I put these diffusers in a few months ago:

http://www.drsfostersmith.com/produ...x=mode+matchallpartial&Np=1&pc=1&N=2004&Nty=1

They are great because they won't dissolve (made out of plastic) and they are black so they blend in well with my background. I bought some black airline tubing, hid these things behind my rock and you can barely notice them. I test them every week when I'm doing my water change - it helps to clear the gunk out of the holes so they don't clog.

Daire

ps...you can adjust the bubble size too. They give off a lot of bubbles.

 

[FishyIdea]

good advice, thanks.

i ordered some of those, plus black tubing, plus check valves.

test once a week.

now should I invest in rechargeable batteries?

I got some black "high quality rubber" air diffusers from Won Brothers earlier, then I remembered salt water and rubber are not a good mix.

 

[starrfish]

Since you are only using them for backup situations (and weekly testing for a few seconds) I don't think you need rechargeable batteries. I would only change the batteries after you have an extended power outage. I'm not sure how long they last during an outage, but I know it's for many hours.

 

[Greg Hiller]

I would not use rechargeable batteries. They usually do not hold a charge nearly as well as alkaline batteries. A pair of alkaline batteries ought to be good for at least two years if not used.

I really like the silica based airstones from Aquatic Ecosystems. They are only a few $ more than cheap airstones. FWIW, I DO recommend airstones rather than just an open tube. An open tube can create more water motion, but I can tell you from some experiments that I performed that you are better off with an airstone if what you are trying to do is keep the oxygen level of your tank up. And, IME/IMO that is what you need to do in a short term power outage (several hours). I lost a bunch of large fish once due to a short term lost of my recirculation pump overnight. When I restarted the pump, the corals (even those that were exposed to air for hours) didn't seem to bat an eye. I didn't loose a single Acro or any coral at all. It was a drag burying the fish though!

FWIW, I built small acrylic brackets to hang my battery powered pumps off the back of the tank (less chance of siphon and MTing of tank). I use a small section of silicone airline tubing (less likely to harden and leak than the cheap stuff) to go from the pump to a check valve, then to a long piece of rigid airline tubing (most the LFS's have this for $0.69 for a 3 ft piece), then another small piece of silicone tubing to the airstone, as close to the bottom of the tank as possible, hidden in the back behind the rockwork. I've never seen much of a problem with the tubing or airstone becoming plugged, but it's a good idea to test it every few months of course.

 

[RichConley]

The best solution for dealing with the siphon issue is ofcourse to get the pumps up above the tank...you can't siphon up.

I'd just be worried about these things getting coated with coraline and no bubbles coming out.

 

[jovreef]

I used a battery air pump when I moved up here and it lasted 3 days constant use...still worked when I switched it on last week to test it.

 

[FishyIdea]

Thanks everyone.

Rich, I think the clogging issue is why Daire tests weekly. I'm going to try and get away with less testing, but I think the testing is probably quite necessary.

Joe

 

[Greg Hiller]

Rich,

>I'd just be worried about these things getting coated with coraline and no bubbles coming out.<

That's why I put mine behind the rock work where there is not enough light to grow any coraline.