Pond circulation   6/21/07
Hi Crew,
<Mike>
My Mom has a pond containing 4000 gallons of water, a variety of flora, but mostly lilies, and some koi and larger goldfish. There is also the annual migration of amphibians to the pond.
<Nice>
I have some of experience with aquaria, but I need to know the turn over rate for a pond of this size.
<At least once per hour... twice is better, and the more "complete" (perhaps leaving the very bottom "level" for settling, venting...) the better>
I believe she is "under-pumped" which is contributing (among other things) to the algae bloom she is complaining about.
Thanks for your help,
Mike
<Is one factor... You/she have read here: http://www.wetwebmedia.com/PondSubWebIndex/pdalgcontrol.htm
and the linked files above?
Bob Fenner>

Aeration in pond 6/29/05
I'm located in Connecticut and installing a submerged aeration system in a pond (approx 1/4 acre in surface size with aver depth of 5 feet). The pond is fed primarily by run off and is relatively still.  24 carps were placed in the pond 15 yrs ago and approx 16-18 are still alive.
The person selling the aeration system says we can clean the hose twice a year by dumping a gallon of Muriatic acid thru the hose.
Do you think this is safe for the fish?
<Mmm, likely not a good idea... Our old service company (Aquatic Life Services) used to maintain several such systems... we found it far better to periodically (once a year or so) to "fish out" the mechanical diffuser (usually a glass-bead "air stone", and bleach it (laundry or swimming pool type) for an hour or so... rinse and re-install... the Muriatic (three molar Hydrochloric) Acid will likely damage the hose, perhaps the diffuser... and your lungs, clothes... btw, Aquatic Ecosystems sells replacements. Bob Fenner>

Pond aeration
Hello crew,
<Karun>
I have just started a small pond 5ftx5ftx1.5ft. I am using an Eheim filter that circulates 3000 litres /hour.
<Great units... do just make sure the electrical connection is out of where it can get wetted>
The pond has assorted plants. I also have about 30 mollies and guppies and 8 red tail black sharks (2 inches each) The pond does not have too much surface movement and no aeration. Will there be enough oxygen in the water? Should I increase the surface movement?
<Good question... I would arrange the discharge "wand" to either discharge some of its "hole/outlets" above water, or at least for the water surface to be rippled by placing it, turning it to discharge near the water surface... alternatively, if you have the means, a good air-pump (my favorite choice, the Tetra Luft series) and maybe attach this to a sponge filter... would be ideal for both added aeration, some filtration, and redundant back-up. Bob Fenner>