water pump too fast for my system?

[cage]

hi everyone!

i am using a barrel for raising fish and half barrel for growing vegetables. i am still very new at this and still trying with empty barrel with no growing mediums inside.
now when the bell siphon kicks in the water level wont drop any lower than the PVC pipe because my water pump is pumping so fast. so half barrel is always full of water. the water pumps water from a 3/4" tube to my grow bed and the drain from a 1" PVC pipe. water wont go any higher but wont drop either and the shop wont exchange the pump because i used it already.
any suggestion anyone?
the max height of the is 2.7 meters and it pumps 2700litres per hour (Lifetech AP5000)
if i use a tube longer than 2.7 meter i think it might lower the water pressure? but would it affect the water pump lifetime in the long run?

[keith_r]

you can divert some of the flow from the pump back into the fish tank, this will accomplish 2 things, it will add aeration, and decrease the flow into your growbed. for a small growbed, i'd probably just stick to a loop siphon

[swamp creek farms]

yeah, what keith said.. i had the same problem with my newest system, just T off of the main line and add a ball valve returning to the FT. Unless your ready to add more GB.

I did that for a while till I added more GBs, and now it runs like a champ

[cage]

thanks thats a great idea! i will eventually add more GB later if everything is going well but i guess a T will solve my problem for now :D

[urbanfarmer]

Also, if you add a ball valve you can control the flow to get it just right.