Filter Intake/Outlet Positioning - 300 gallon tank

[Arrow1oo]

I’m in the process of setting up my 300 gallon tank (8’ long x 2’ wide x 29” high).

Since I plan on stocking some big SA cichlids, I want to run a sump with two returns as well as two additional fx6 filters for some extra polish.

I have an internal overflow in the center but I wanted to see what placement of my intakes/returns would be optimal. I plan on using spray bars for my fx6 outlets.

Here are some drawings of the two options I’m considering:

Also open to other suggestions.

 

[Arrow1oo]

Bump

 

[danotaylor]

I don’t understand your drawings.
What do you mean by “an internal overflow in the center”?
Does it have a weir?
Are you gonna be drilling your own holes?
A picture of the actual tank may help

 

[Arrow1oo]

I don’t understand your drawings.
What do you mean by “an internal overflow in the center”?
Does it have a weir?
Are you gonna be drilling your own holes?

Sorry, my terminology might be off. It’s just a weir with holes drills behind it.

Just wanted to see which flow pattern would be best.

 

[danotaylor]

A trapezoid style weir in the center at the rear of the tank then?
In your 2 options the intakes are in different places. How can that be possible if you have a weir in the rear of the tank and you’re not drilling more holes?
How many holes are behind the weir?
Are the drawings looking downwards from the top?

 

[Arrow1oo]

Yeah a trapezoid weir. Those intakes aren’t for my sump, those are for the fx6’s I intend on adding to help.

In my drawing I forgot to add it, but the drains for the sump will be right between the two sump returns.

I’m mostly asking about the fx6 intake placement and what orientation will get them the most value.

Sorry for the confusion

 

[danotaylor]

Ok, now it makes sense. The FX6 drains. Gotcha.
So there’s only 1 overflow weir for the sump. 4 holes. 2 drain, 2 return.
If it were me I’d place the FX6 return inside the weir as far from the drains as possible so they’re not in view in the main tank. Position your spray bars and sump returns to try to lift the solid waste to the overflow of the weir.
TBH if you’re mainly using the FX6 to polish, 1 would be sufficient and an additional wave maker or 2 to lift the waste to the overflow of the weir.

 

[Arrow1oo]

So I’ve setup another tank before where I actually plumbed two fx4’s into drilled holes and it worked amazingly. Still running to this day.

My concern is, if I put one or two fx6 intakes inside the weir, would it drain the water (from behind the weir) faster than my tank can replace it?

I’ll already have a full siphon going (running a herbie drain) so I don’t want to run into that issue.

The whole reason I’m using fx6’s is because with a herbie my tank will only have like 1000 gph at most (since it’s a 1” drain with a herbie setup). I wanted some more turnover since I plan on keeping SA Cichlids

 

[danotaylor]

The rate the water flows over the weir is determined by the rate water is flowing into the tank.
When I fill my tank, I turn the sump pumps off. I fill into the main tank until the water overflows and fills the sump to the level I want it. Turn the faucet off. I plug the pumps back in and turn them on, and the flow rate from the main tank back to the stump is determined by the flow rate of the pumps delivering water to the main tank. Meaning if I unplugged one of my two pumps, nothing changes except the gallons per hour that are turned over between the tank and the sump. The sump level & the tank level stay constant (except for evaporation)
If for some reason, your sump pumps stopped, the flow rate from the FX6 would still cause water to overflow behind the weir and the FX6 wouldn’t run dry. If the FX6 stopped running the flow rate from your sump pumps would keep water flowing over the wire and into the sump. With the FX6 & the sump pump running the inflow to tank and over the weir is relative to water being delivered to main tank.
Seems confusing, but it’s actually very simple. Volume of water in to the main tank = volume of water out over weir. It doesn’t matter if you have 1 or 10 pumps running

 

[Arrow1oo]

The rate the water flows over the weir is determined by the rate water is flowing into the tank.
When I fill my tank, I turn the sump pumps off. I fill into the main tank until the water overflows and fills the sump to the level I want it. Turn the faucet off. I plug the pumps back in and turn them on, and the flow rate from the main tank back to the stump is determined by the flow rate of the pumps delivering water to the main tank. Meaning if I unplugged one of my two pumps, nothing changes except the gallons per hour that are turned over between the tank and the sump. The sump level & the tank level stay constant (except for evaporation)
If for some reason, your sump pumps stopped, the flow rate from the FX6 would still cause water to overflow behind the weir and the FX6 wouldn’t run dry. If the FX6 stopped running the flow rate from your sump pumps would keep water flowing over the wire and into the sump. With the FX6 & the sump pump running the inflow to tank and over the weir is relative to water being delivered to main tank.
Seems confusing, but it’s actually very simple. Volume of water in to the main tank = volume of water out over weir. It doesn’t matter if you have 1 or 10 pumps running

I get what you’re saying. For some reasons I thought there was a limit to how much water could reasonably flow from the display to the weir, but as long as the water is being returned at an equal rate I’m fine.

Gotcha, so my next question is, should I try to plumb my one fx6 IN PLACE of one of my simple returns? The hole accepts a 3/4” pipe so I feel like I could plumb it in. But I’m not sure if:

1. It’s worth it as I could probably just run the intake over

2. Will one return be able to properly handle my drains gph without needing to throttle my drain down too much

Appreciate all the help by the way.

Edit: I might just snap it over the top like you suggested. It seems to fit so why not have the extra return from the sump for redundancy