Need for the Aeration of the fish tank?

[Bob Vento]

I thought that the process of the bed water flowing fast back into the fish tank provided the oxygen for the fish?  I also used a suggestion from another member ... of drilling angled holes in my grow bed drain pipe to create a venture affect thus introducing more oxygen into the fish tank. My system is flood and drain 24/7.

However, the more I read ... a lot of you are providing extra aeration to your tanks... is that necessary or just a precautionary measure?

If so ... what would ya'll suggest I buy, for a reasonable price, for aerating my fish tank to insure proper oxygenation of the water for my fish?

Sure would like some advise and comments. 

Thanks,
Bob

[matthew ferrell]

My system crashed, so that's what caused mine.  I have been adding components, and having a hard time getting enough nitrogen in the system.  Those little fish don't eat enough.  So I added maybe a little too much fish emulsion.  Oops.

I would almost stick to my original comments except I don't want to be the cause of someone else's accident.

[matthew ferrell]

FYI, gulping.  I lost only one, but I expect a stinky surprise in 3 days.

Also the power was only out for a couple of minutes.  Again the crash was my fault.

[Bob Vento]

Ya'll

I am only putting in about 12- 20 fingerlings to my newly cycled up system (200 gallon tank) this Saturday, I think I might be able to wait on the air pump for a while until the little ones begin to grow and demand more oxygen.

I think I have some time, don't you? 

Bob

P.S. Sorry for your loss Matthew.

[matthew ferrell]

It might seem awful, but I have something like 30,000 fish, so one or two doesn't even cause a tear anymore.  However thanks for the consideration. 

Also I think you will be plenty fine with that.  In 400 gallons I have something like 100 fish, most are 4-6 inch koi, with one 3.5 pounder.  The system needs more fish, and less amendments.

[TCLynx]

I like to have an air pump handy for battery backup and sometimes it helps stir things up and keep the solids from collecting in the corners (if you have them) and in case anything goes wrong.  Even if I'm not running it constantly it can be handy to have an air pump and stones in case you need to put a fish into a salt bath or something because of injury or illness.  Or if an algae bloom takes off with fish in the system, you definitely want to add extra aeration overnight and things like that but you can probably get away without it for a time.

Last year I had been running the bluegill system with only the water returning from the grow beds (not even enough extra pump power to do a bypass at the time) and they did fine until about this time last year and suddenly they quit eating very well (water temp was staying over 80 F even overnight) so I added about 1 CFM of air into the tank with a single 12 inch airstone.  Fish started eating well again and all was good.

[Bob Campbell]

Very good picture, it clearly shows why air is important!  Thank you for posting this link.

I asked Forest, my friend and hydroponic guru, if it might be due to water movement.  He felt strongly that it's the improved oxygen in the water rather than water movement.  I'm still on the fence about that, but Forest really knows about hydroponics so I tend to believe what he says.

Rebecca B said:

There's another discussion  http://aquaponicscommunity.com/forum/topics/aeration-more-than-diss... that has a picture of an air pump and DO and growth on a raft that's pretty illustrative.

[Tom OBrien]

Can I ask what you are using to measure DO? I've just been running the air pumps and hoping for the best with my trout tanks because the test kits I've seen are not real cheap.

matthew ferrell said:

As I wrote this the power went out.  So I strolled over to my system and all my fish were up.  DO was .8.  Call me a liar.

[TCLynx]

Testing DO is either not very easy using the good but inexpensive test kits or it is not accurate using the cheaper but easier test kits or there are meters but they tend to be on the costly side.

For a backyard system, most people get by without the meters and test kits but for commercial operations like Mathew's, investing in a meter becomes more important.

[matthew ferrell]

my meter cost 700, the probe cost 700.  You can get away with a ysi that is about 550, but I am a fan of the odo stuff now.

Like TC said, its not cheap, but when you are invested like we are, these are just the normal tools of the trade.

[matthew ferrell]

I agree with your friend.  I also think direct contact with air bubbles is a big help.

Bob Campbell said:

Very good picture, it clearly shows why air is important!  Thank you for posting this link.

I asked Forest, my friend and hydroponic guru, if it might be due to water movement.  He felt strongly that it's the improved oxygen in the water rather than water movement.  I'm still on the fence about that, but Forest really knows about hydroponics so I tend to believe what he says.

Rebecca B said:

There's another discussion  http://aquaponicscommunity.com/forum/topics/aeration-more-than-diss... that has a picture of an air pump and DO and growth on a raft that's pretty illustrative.

[Jon Parr]

Hope your fish are alright, Matthew. I personally agree with Matthew, in that an air pump is not needed, and with George about redundancy. Every DO problem I've ever had has been the direct result if NOT having a backup system in place. Whether you opt for an air pump or another water pump, you should always have two pumps (or more) on two circuits, preferably one of them on battery. Two pumps doesn't mean twice as much power or twice as much initial cost, as working together they can perform the optimum duty as a one pump design, or independently cover a minimum load.
In a small system, I usually run two GB's, with two pumps, one pump designated for each. One is on grid power, one on battery. If one fails, the other maintains the DO. F&D beds can last a couple of days without pumping (depending on the crop and the heat), so fish are what's being saved. Air pumps, however, are long-lasting like Bob Campbell said, and require no maintenance, and no bio-slime to worry about. Another safety is to use large surface area FT, so nature does the aeration. I have several 6 and 8 foot diameter 18" tall wading pools with no pumps at all.

[TCLynx]

I wouldn't say air pumps are NO maintenance, most of them do require diaphragm replacements probably yearly and air stones may need rejuvenation when they get clogged up but that is also probably more of a yearly thing rather than weekly like cleaning pump screens might be for some set ups.