Adding 2nd pump to save electricity

[pwcornish]

My existing Sequence pump is costing me $130/month to run since I am on tier 4 PG&E rates (.41c/kWh). I want to reduce the cost. Given that the biological filter needs continous water to avoid the bacteria from dieing, I can't just put a time switch that turns it off at night. I am considering two options and would appreciate anyones inputs:
1) The simplest solution would be to add a time switch that turns off the pump in two hour increments - not long enough for the bacteria to die. If I use a 2 hour on, 2 hour off cycle I could save 50% on my electricity usage.
2) Add a small secondary pump that will circulate enough water to keep the bacteria alive and cost much less than the high flow pump which is then only turned on when needed. I'd like to do this without tearing out my existing pump. I am wondering if it's possible to add a 900 gph pump in series with the existing 3000 gph pump using a bypass arrangement that would allow the high flow to bypass the small pump when turned on. (I have a diagram but can't post it since I must have 10 prior posts before allowed to add a link - please contact me via e-mail and I will send you the diagram - (e-mail address removed)). As pointed out in the diagram, the big question is whether the small pump would be able to pull water through the big pump when the big pump is turned off.

 

[c2c7390]

i wouldnt want to do that...in my opinion you shouldnt shut off a pump to the filter...you might want to look into solar powered pumps...sure it costs a lot but in the end youll save a lot of money

 

[pwcornish]

Could you be a bit more explicit as to your concern with turning off the power in 2 hour increments? Adding a secondary pump could be done (solar or otherwise) - the complicated part is plumbing it in with the existing pump as I described in the post.

 

[c2c7390]

im worried that the constant turning on and off may prematurely wear out the pump...even when off the pump would still be consuming energy just like your TV does when it is turned off...how high is your pump pumping would it be too hard to change it out for a more energy efficient one
and about the pump pulling water through the larger pump...this may cause extra strain on the smaller pump

 

[pwcornish]

I agree that turning the pump off and on frequently will add stress. I'm inclined to go with the secondary pump approach. I'm curious to find out if anyone has tried the approach of putting a small secondary pump with a bypass in series with the primary pump (requires diagram to explain) with time switches to the turn the pumps on and off.

 

[c2c7390]

i havent tried plumbing a second pump after the existing pump...i use 2 pumps to draw water out of my pond...i just looked at your diagram and i suggest that you just bypass the existing pump like this

oops i took out the check valve...you might want to keep that there

 

[c2c7390]

and for everyone that wants to see the original diagram this is what it was

 

[c2c7390]

is the water forced through the bio filter
and then goes up to the upper pond

i will also suggest that you make sure that when youre switching pumps make sure that your pumps "on" time over laps just a little

 

[pwcornish]

Yes, the output of the bio filter rises 10' to the upper pond. I agree that your diagram would be a safer approach. The problem is that I want to put the 2nd pump close to the bio filter and electrical panel. The main pump is 30 ft away (hence the dotted lines in the pipe) and in an underground enclosure which I don't want to tear up.

 

[c2c7390]

Yes, the output of the bio filter rises 10' to the upper pond. I agree that your diagram would be a safer approach. The problem is that I want to put the 2nd pump close to the bio filter and electrical panel. The main pump is 30 ft away (hence the dotted lines in the pipe) and in an underground enclosure which I don't want to tear up.

you can still do that you would just need a second line running to your leaf catcher...but if you dont want to do that just make it run from the closest part of your lower pond...

could you send me a picture of your pond so i can help you plan a route for the plumbing

 

[DrCase]

Do you know how many watts your pump uses????

 

[koiguy1969]

I run a air pump in my bio filter anyway..just to insure plenty of oxygen for my bacteria. just a cheap one with a couple of 1 or 2 inch air stones. the pump costs about $3.00 a month to run. my 1000 gph pump costs about $10.00, and according to its stats and formula for figuring costs, my new 1900gph pump will cost about $12.00. they are tetra ponds. i would have to close my pond if it cost me like it costs you. they werent expensive but have 3 year guarentees.

 

[pwcornish]

that's a good thought......but I'd need some kind of filter to stop the inlet to the 2nd pump from clogging. any suggestions on that? the closest portion of the lower pond is only 10 ft or so from the location where the 2nd pump would be so running a line would be possible.....the water there is just below the falls and is shallow though....maybe 6" deep.....I really appreciate all the thought you are putting into this!

 

[pwcornish]

my pump is consuming 400W, that's 288kWh/mo. at tier 4 costs of .41c, that's $120/mo. I haven't heard of an air pump for the bio filter. I'll check that out.....

 

[c2c7390]

that's a good thought......but I'd need some kind of filter to stop the inlet to the 2nd pump from clogging. any suggestions on that? the closest portion of the lower pond is only 10 ft or so from the location where the 2nd pump would be so running a line would be possible.....the water there is just below the falls and is shallow though....maybe 6" deep.....I really appreciate all the thought you are putting into this!

you could use some sort of strainer and or mesh to cover the intake