Abyzz A400 or other large pump users - Please help with my question

[WhatCouldGoWrong71]

I am working towards a build where the display is close to 400G. I purchased an Abyzz A400 for the closed loop. The questions surrounds the hole that my builder (GC) will cut for the drain for the closed loop. The A400 has a 2 inch inlet. Should the hole be 2 inches so that there is zero restrictions to the pump? Builds I have seen some have 1.5" and some have 2" for similar setups. I have to get this information into my builder today/tomorrow. There will be 4 closed loop returns 2 - 1" and 2 - 1.5".

 

[piranhaman00]

Abyzz for closed loop?? Much cheaper options of same power, abyzz would make a better return pump

I was always under the impression that the inlet of a pump cannot be restricted at all but the outlet can. So you would need a 2” drain for the inlet

 

[homer1475]

You cannot choke down the inlet of the pump(it will cause cavitation, and not supply the pump with enough water(gravity fed)).

You can choke down the outlet as this is just like adding head.

 

[WhatCouldGoWrong71]

Abyzz for closed loop?? Much cheaper options of same power, abyzz would make a better return pump

I was always under the impression that the inlet of a pump cannot be restricted at all but the outlet can. So you would need a 2” drain for the inlet

lol, I don’t need to turn my sump 45 times an hour. Going for no power heads, well, there will have to be 2 in case of power failure while I am not home. It was used for 2 months and the guy let it go for 1/2 price. Couldn’t pass it up. I’m OK with overkill.

 

[WhatCouldGoWrong71]

You cannot choke down the inlet of the pump(it will cause cavitation, and not supply the pump with enough water(gravity fed)).

You can choke down the outlet as this is just like adding head.

That’s what I thought and the feedback I was looking for.

 

[WhatCouldGoWrong71]

lol, I don’t need to turn my sump 45 times an hour. Going for no power heads, well, there will have to be 2 in case of power failure while I am not home. It was used for 2 months and the guy let it go for 1/2 price. Couldn’t pass it up. I’m OK with overkill.

Even got his BRS receipt. Small world, guy lived like 3 blocks from me and we never crossed reefing circles prior.

 

[homer1475]

Not an abzz, but I won a huge MRC pump on here I use for my mixing station.

When I first plumbed it I used 1", where the inlet of the pump was 2". It would not push water, and cavitate inside the volute.

When I reached out to MRC, they explained in some very sciency way on why I had to go with the 2" on the inlet, but could choke down the outlet.