Bidirectional tidal flow

[lastlight]

If you just tee off your closed loop pump and have a valve on either side of the tee why do you need 4? Are you concerned about valving off inlets on either side too? If the inlets were more or less centered why not use just 2 valves?

I think a guy on RC bought a morized butterfly valve or something like that by Hayward. They're pricey but from what I read the pricey ones are extremely reliable.

Overall likely cheaper to use a pair of DC controlled pump for each side. Red Dragon is apparently releasing new pumps as the previous generation had issues. I've heard good things about similar pump but can't quite recall the maker or the name sorry.

[golf nut]

Originally Posted by lastlight

If you just tee off your closed loop pump and have a valve on either side of the tee why do you need 4? Are you concerned about valving off inlets on either side too? If the inlets were more or less centered why not use just 2 valves?

I think a guy on RC bought a morized butterfly valve or something like that by Hayward. They're pricey but from what I read the pricey ones are extremely reliable.

If you are only switching every 5 hours they will work fine, the rapid sequencing is their downfall.

[sphelps]

Originally Posted by lastlight

If you just tee off your closed loop pump and have a valve on either side of the tee why do you need 4? Are you concerned about valving off inlets on either side too? If the inlets were more or less centered why not use just 2 valves?

I think a guy on RC bought a morized butterfly valve or something like that by Hayward. They're pricey but from what I read the pricey ones are extremely reliable.

If you had a common suction 2 valves would work. I think ideally to create the cross flow you need a suction on one side and the output on the other so in this case you would need 4, which is what I was talking about.

[golf nut]

Originally Posted by sphelps

If you had a common suction 2 valves would work. I think ideally to create the cross flow you need a suction on one side and the output on the other so in this case you would need 4, which is what I was talking about.

Here is a quick bad video, there are 8 holes drilled , 4 at either end of the tank for coverage, the lower holes are C/L feeds, the uppers are C/L returns, they are being switched by a common drum, when water enters top right it is being removed bottom left and vise verse, if you watch carefully you can see the pellets being drawn in from the bottom. the pellets are an injection molding pellet about the same specific gravity as water.

just one pump.


http://www.youtube.com/watch?v=XxlOvNN-OPE

[StirCrazy]

Originally Posted by golf nut

Here is a quick bad video, there are 8 holes drilled , 4 at either end of the tank for coverage, the lower holes are C/L feeds, the uppers are C/L returns, they are being switched by a common drum, when water enters top right it is being removed bottom left and vise verse, if you watch carefully you can see the pellets being drawn in from the bottom. the pellets are an injection molding pellet about the same specific gravity as water.

just one pump.


http://www.youtube.com/watch?v=XxlOvNN-OPE

all that looked like was a ocean motion device with a common inlett and two outlets.

Steve

[golf nut]

Originally Posted by StirCrazy

all that looked like was a ocean motion device with a common inlett and two outlets.

Steve

Except is isn't, both the inlets and the outlets reverse to direct flow through the tank and also to be pulled out on the opposite end, each is aiding the other.

[golf nut]

This is one of a pair that were installed an a good sized tank in a public aquarium, these were equipped with proximity switches and then driven by a PLC, this would alternate flow as in the video but enable to turn the tank clockwise or anticlockwise when viewed from above, ideal in a through wall viewed tank.

[lastlight]

Here we go:

Abyzz pumps by Venotec.

http://www.korallenzucht-wendel.de/g...n/venotec.html

http://www.youtube.com/watch?v=wFGASFHEWL8