seanm001
Member
I've got a 54-gallon bowfront tank and I'm looking for input / advice about the best flow pattern for this tank shape. There is an internal overflow that cuts a diagonal across the back corner. The rock is arranged in a semi-circle with a minimum of 2" of clearance on all sides. There is a Catalina 1800 retun pump that, after head loss, pumps about 400 gph from the sump. I've also got a Tunze 6025 that is rated for 660 gph. Combined, that gives me 19x flow per hour.
As I originally set the flow up, I had the return flow from the sump coming out at the top of the tank, angled downward at maybe 10 degrees or so and shooting at the front wall. The flow goes through a LocLine nozzle, so it's pretty focused. I had the Tunze on the left wall, all the way at the back and near the sand to draw flow across the sand and from the back, shooting upward at the top front. The two flows ran across the front panel, met in the middle, and flowed back through the rocks. The two pumps were basically blowing in opposite flow directions. This arrangement was great for keeping particulates suspended, but didn't seem to give enough flow across the sand to keep cyano away.
So, I changed the arrangement and moved the Tunze to the top right corner at the front of the tank, with the flow going diagonally down the front panel to the lower left corner. The flow from the sump return shoots in the general direction of the Tunze, so everything flows in the same direction. My hope was that the gyre effect would increase flow across the sand. I think that's the case as the cyano has decreased, but it seems the inner part of the semicircle of rocks has become a dead spot and I see particulates and waste on the sand there sometimes.
I liked the first arrangement better as the Tunze was hidden behind the rockwork and did a really good job of keeping food and particulates suspended for removal by the overflow. But, if the population of cyano is used as an indicator, then the second arrangement is better for flow across the sand.
Are there any others out there with a similar tank shape who would like to share their flow patterns and what works or doesn't work for you? Anybody got any advice about other arrangements I can try to minimize dead spots and get proper flow in this tank?
Thanks,
Sean
As I originally set the flow up, I had the return flow from the sump coming out at the top of the tank, angled downward at maybe 10 degrees or so and shooting at the front wall. The flow goes through a LocLine nozzle, so it's pretty focused. I had the Tunze on the left wall, all the way at the back and near the sand to draw flow across the sand and from the back, shooting upward at the top front. The two flows ran across the front panel, met in the middle, and flowed back through the rocks. The two pumps were basically blowing in opposite flow directions. This arrangement was great for keeping particulates suspended, but didn't seem to give enough flow across the sand to keep cyano away.
So, I changed the arrangement and moved the Tunze to the top right corner at the front of the tank, with the flow going diagonally down the front panel to the lower left corner. The flow from the sump return shoots in the general direction of the Tunze, so everything flows in the same direction. My hope was that the gyre effect would increase flow across the sand. I think that's the case as the cyano has decreased, but it seems the inner part of the semicircle of rocks has become a dead spot and I see particulates and waste on the sand there sometimes.
I liked the first arrangement better as the Tunze was hidden behind the rockwork and did a really good job of keeping food and particulates suspended for removal by the overflow. But, if the population of cyano is used as an indicator, then the second arrangement is better for flow across the sand.
Are there any others out there with a similar tank shape who would like to share their flow patterns and what works or doesn't work for you? Anybody got any advice about other arrangements I can try to minimize dead spots and get proper flow in this tank?
Thanks,
Sean
