Is this flow rate enough?

[Magzire]

Just upgraded my pond, its now 1800l from 400l. My pump is rated at 1900 LPH (Laguna PowerClear Multi 3500). I have 25mm hose connected directly to the base output (disconnected the waterfall connector) that bypass to two external filters (1st external filter feeds the second filter back to pond)
I measure the flow rate going back into the pond which is only 660 LPH. (fills 11l per 60 secs)

The stock is 14x6" goldfish.
Is the flow rate enough?

I do have a spare Hozelock Cascade 1500, which I measured its flow rate at 1200 LPH (20l per 60 secs). However it doesn't have a UV.
Should I ditch the Laguna PowerClear Multi 3500 for the Hozelock Cascade 1500?

 

[Meyer Jordan]

With your present configuration, I would say that your 1900 lpg pump is too small. For this stocking level (14 x 6" goldfish), you need a flow rate of at least 2700 lph with biofiltration compatible to this higher flow rate.

 

[Magzire]

I thought so. Will bite the bullet and get a Oase Aquamax Eco Classic 3500

 

[Usman]

Just upgraded my pond, its now 1800l from 400l. My pump is rated at 1900 LPH (Laguna PowerClear Multi 3500). I have 25mm hose connected directly to the base output (disconnected the waterfall connector) that bypass to two external filters (1st external filter feeds the second filter back to pond)
I measure the flow rate going back into the pond which is only 660 LPH. (fills 11l per 60 secs)

The stock is 14x6" goldfish.
Is the flow rate enough?

I do have a spare Hozelock Cascade 1500, which I measured its flow rate at 1200 LPH (20l per 60 secs). However it doesn't have a UV.
Should I ditch the Laguna PowerClear Multi 3500 for the Hozelock Cascade 1500?

u have 2 pumps then u can use them both to good effect , i use spare pump for additional water fall at the day time to increase flow and aeration and i switch it off at nite , it also depends from which ways ,filters and obstacles water is flowing in the process to have gas exchange even if its 600LPH , if its going thru few medias and dropping from fall its doing quite bit for fishes .

 

[Magzire]

Not a bad idea i guess.
.

 

[Magzire]

your 1900 lpg pump is too small. .

Rated for 1900 lpg, but only 660 lpg

 

[Meyer Jordan]

Rated for 1900 lpg, but only 660 lpg

A 1900 lph pump is not sufficient for this high of a fish load in this size pond. You need at least 1.5 times the volume of the pond being circulated per hour. This equates to a 2700 lph pump or more correctly a pump that will supply 2700 lph.

 

[Usman]

from my understanding ur not overstocked neither lacking flow , rule is 1 inch fish per 1 Gallon so ur pond has 475G , ur fish is 14x6 ie 84 inch

other rule is circulating once total water for goldfish . ur fulfilling that in a way that ur fish load is less then its capacity . as recommended flow for pond without fish is half , i believe its more about filter media and design aswell as aeration these things are important then u can even have many more in same system .

am i missing something.... u can have 15 more easily if u can cycle pondwater once per hour

 

[Meyer Jordan]

rule is 1 inch fish per 1 Gallon

If this were true then one could have 4 24" Koi in 96 gallons of water. The idea that the stocking levels for goldfish differ from the levels for Koi is erroneous. A 6" fish, regardless of specie, will. with few exceptions, generate about 6 mg/l of Ammonia per day.
The only difference is that Goldfish are a more durable and forgiving fish than Koi, but that does not justify not providing the healthiest, stress-free environment possible.

as recommended flow for pond without fish

Water flow (circulation) in a fish-less pond is not essential and can be omitted.