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

[Bob Campbell]

Air pumps are very inexpensive.  It's just good practice to be on the safe side, and later as your fish grow, so will their oxygen demand.  I've had an Active Aqua 2 outlet air pump running continuously for a couple years.  It's very quite and puts out a strong air pressure. I would recommend this pump

[George]

Even though my flood and drain produces a lot of aeration, I installed a 12-volt bilge pump with spray bar for redundancy.  Now if the grid current or pump goes down, my fish should be ok until I can deal with it.  Warm water holds less oxygen so there is that to consider during the summer.  My 12 volt is solar/battery powered but you could rig this with a good deep cycle battery/charger too.

[TCLynx]

Water returning to the fish tank does provide some aeration, but is it enough is usually the question.

And in a HOT climate the hot season can mean very warm water that doesn't hold much Oxygen in the first place and if you have a heavy fish load or feed them a lot when it is hot and they are hungry, you can find the oxygen quickly used up.  And some types of fish need more dissolved oxygen than others but even tilapia will eat and grow better when there is plenty of aeration.

So I would suggest an air pump or some other pump added for supplemental aeration.

If you use an air pump You want to provide about 0.25 CFM (cubic feet per minute) per 100 gallons if you are going to be running a heavy fish load.  So for a 200 gallon tank you would need an air pump that can provide about 0.5 cfm at 2 psi.

[Bob Vento]

Is this the air pump you are referring too?

http://www.amazon.com/Hydrofarm-AAPA7-8L-3-Watt-7-8-LPM-Outlets/dp/...

if not can you please give me a link to the proper air pump?

Regards,
Bob

Bob Campbell said:

Air pumps are very inexpensive.  It's just good practice to be on the safe side, and later as your fish grow, so will their oxygen demand.  I've had an Active Aqua 2 outlet air pump running continuously for a couple years.  It's very quite and puts out a strong air pressure. I would recommend this pump

[Bob Vento]

TC, George and Bob,

I should have added the point that I am also providing a constant flow of diverted water flow back into the fish tank at all times. This pipe also has the diagonal holes (the venturi if you will)  in the pipe to introduce air into the water flow.

The air bubbles produced by both the constant flow pipe and the drain pipe seem to go deep, about 10 " down into the fish tank.

I will however, buy an air pump to supplement the oxygenation of the water for my fish, which will be added this Saturday WooHoo !!!!

How many air stones do you all use in a 200 gallon tank? Which types do you use? Should I buy a pump with multiple outlets or use a valve system?

Bob

P.S. Every time I turn around I have to buy additional stuff SHEESH! Is this a modern day money pit?

[George]

That has been my experience.  At present I'm considering a new charge controller, 2nd fish tank and no telling what next. 

Bob Vento said

SHEESH! Is this a modern day money pit?

[matthew ferrell]

Acid bath.

Bob Campbell said:

Yes that's the one I have.  They also make others with more outlets.  I like the big air stones.  My favorite is about 4" long and 1-1/4" in diameter.  $4.50 .   

One thing I've noticed is they tend to loose efficiency after a while.  I wonder if anyone knows of a way to clean an air stone and restore it's bubbly nature.

Bob Vento said:

Is this the air pump you are referring too?

http://www.amazon.com/Hydrofarm-AAPA7-8L-3-Watt-7-8-LPM-Outlets/dp/...

if not can you please give me a link to the proper air pump?

Regards,
Bob

Bob Campbell said:

Air pumps are very inexpensive.  It's just good practice to be on the safe side, and later as your fish grow, so will their oxygen demand.  I've had an Active Aqua 2 outlet air pump running continuously for a couple years.  It's very quite and puts out a strong air pressure. I would recommend this pump

[matthew ferrell]

I am going to go against the group.  I have not found it necessary to ever aerate my system, even the 55 gallon fish tank in the Alabama sun.  That being said, there is some saying about being safe and sorry.  I am to hard headed to listen to it.

[matthew ferrell]

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.

Bob Campbell said:

I agree that it is not necessary.  My Koi pond is over populated and has no aeration, and they are fine in the summer heat.   But since we are  looking for the edge to produce maximum growth, and avoid problems associated with high populations it seems like a small price to pay.  

One thing I've found different about raising fish as a product in an aquaponic system is that conditions change all the time. Where as raising ornamental fish and plants seems to always be on automatic with little concern for nutrient take up and the compromises made to balance the requirements of fish and plants.  Both plants and fish will benefit from aeration so I lean toward providing a lot of air.  If the fish are strong, and not stressed they will be less susceptible to problems.

I have had the best luck with my raft system compared to my ebb and flow gravel beds.  Transplants seem to incur far less shock in the raft system and the growth rate seems to be better.   I also believe keeping some gravel in the bottom of the raft tank with an air stone buried in the gravel is very advantageous.  But this is just my unscientific opinion. I have not documented these observations. 

matthew ferrell said:

I am going to go against the group.  I have not found it necessary to ever aerate my system, even the 55 gallon fish tank in the Alabama sun.  That being said, there is some saying about being safe and sorry.  I am to hard headed to listen to it.

[Ryan Chatterson]

At very low densities, maybe pump return is fine but I'm a fan of supplemental aeration or pure O2 for dense culture.

[Rebecca B]

Good catch, Matthew!  Whew!

If the power goes out, having an air pump or not isn't going to be your issue---but if your water pump fails and you have an air pump, you will have bought some extra time---as George 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.

[George]

Up, as in belly up or gulping on the surface?  Amazing timing. 

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.