Is this pump too big?

[Swingline77]

I'd posted in another thread that I'm setting up a tank for abalone for an amateur science experiment, and the aesthetics of the tank aren't important. I will not be using a sump (at least not now), but will have live rock in a 90 gallon tank. I might have plants. A critical component of the system will be a cooling system, which can handle approximately 500-800 GPH flow. A pump, the Pan World NH-50PX offers a max flow of 590 GPH. In some ways, this seems pretty good. However, I came across another pump for sale used that offers about 1100 GPH flow. I'd like to get this pump, because it's used, and I can save some money (or not, it will use electricity).

If I were to get the larger pump, I'd cut down the flow to the cooling system with a valve, so as not to exceed its specs. The rest of the flow would be diverted to various places within the tank via a manifold system. My concern with all this is that this might be too much water velocity. Unfortunately, I won't really know until it's set up. What's your gut feeling, though? Does this seem like too much, or just right? Thanks.

 

[Swingline77]

I'd posted in another thread that I'm setting up a tank for abalone for an amateur science experiment, and the aesthetics of the tank aren't important. I will not be using a sump (at least not now), but will have live rock in a 90 gallon tank. I might have plants. A critical component of the system will be a cooling system, which can handle approximately 500-800 GPH flow. A pump, the Pan World NH-50PX offers a max flow of 590 GPH. In some ways, this seems pretty good. However, I came across another pump for sale used that offers about 1100 GPH flow. I'd like to get this pump, because it's used, and I can save some money (or not, it will use electricity).

If I were to get the larger pump, I'd cut down the flow to the cooling system with a valve, so as not to exceed its specs. The rest of the flow would be diverted to various places within the tank via a manifold system. My concern with all this is that this might be too much water velocity. Unfortunately, I won't really know until it's set up. What's your gut feeling, though? Does this seem like too much, or just right? Thanks.

It seems I can't edit the post, so I'll just post a reply. Since abalone frequent intertidal areas, excess flow won't be a problem from this perspective. What concerns me, however, is having smaller pieces of live rock moved around. Is this a concern, or would I need much higher velocities for this to be a problem? Thanks.

 

[Sailingeric]

One thing to keep in mind is that GPH is at the pump it self. You will need to account for loss in the pipe and head height. A BRS video I saw says it is best to figure about a 20% loss by the time it hits the tank. So your bigger pump will not be putting out 1100 GPH at the end.

 

[Super Fly]

the recommended water flow is 3-4x water volume so the Pan World size seems appropriate since a sump will not be used. Getting a bigger pump and then reducing it's flow via valve would seem to be a waste. The 1100gal/hr pump is definitely overkill for that size tank and would create way too much flow.