Thinking the pumps are too big - opinions?

[PamBrent71]

Tank is a 80 gallon (65/15) RedSea 300XL. The pumps are Neptune WAV pumps, 2 of them. They work, the Apex controller does a nice job varying the flow ... But they're set to 1%.

1 percent is the smallest setting you can use. And when I feed the clowns & turn off one pump, the frozen mysis shrimp make circles in the tank pretty quickly (works well for the clowns, they don't have to do anything but sit there and food comes to them). Maybe I don't understand the pump configuration well, but it seems like 2 of these is overkill for this size tank - am I wrong?

RPM on the impeller is 1875 & 1882 (range is 1800-4200)
Internal temp is 42% (normal is 40-50%)
FLO is 5.2 overall (3.6 on one side, 3.8 on the other). Apex says "FLO is a general measurement of water movement that is derived from pump performance and the volume of water in the aquarium" and the scale is 0-10.

A couple corals are not happy, and I'm wondering if our flow overall is just too high. A Paly and a Clove are very sad, the clove is shrinking and the Paly is closed up. These are 2 of the first 4 corals in the tank ... and water parameters are both "good" and "fine", so flow is the next culprit. Or light, but we tried moving the clove lower in the tank and it looks WORSE so I don't think we're over-lighting them. A mushroom coral is happy and so is a second coral that I think is a leather. If it IS flow, I don't have a lot of room to move on the settings, but I could direct them toward the back wall and hope that disperses the flow a little better.

Actual water parameters below:
pH - varies 7.83 to 8.08, average is 7.92 (could be higher).
ORP has been climbing from 188 to 221
Salt is 32 - 32.77 (little low)
Ammonia is 0
Nitrate has been falling, from 25 to 5
Alkalinity is 7

 

[this is me]

I don’t think it’s too much flow.
1%?

 

[PamBrent71]

I don’t think it’s too much flow.
1%?

Yeah, the pump is set to 1% on the Apex Fusion , which seems crazy low. The clove looked like it was getting buffeted by the flow so we moved it. More bits of the clove continued to die for a couple days but it does seem to be reaching/extending the remainder now. They currently sway but do not flail anymore.

The BTA is happy, has good feeding response. I checked the transit time and a mysis shrimp makes one lap in just over 20 seconds.

"Easy" corals are not so easy it seems.

 

[coralfishreef]

Probably fine for a SPS tank. 2 of those might be too much for anything else depending on the rock scape. Have you tried running just 1 or putting them higher up? If you are running bare bottom you could also try them low in the back of the tank facing each other or just 1 low in the back.

I had 2 XF250 gyres rated at 5300 GPH each running at the lowest setting in a Red Sea Reefer 250, the previous version of the XL 300. The gyre flow was great, there were no dead spots in the tank, and the sand bed moved but didn’t dust storm. The gyre flow at lowest speed was good for SPS, but LPS and everything else was getting battered no matter where they were placed. The gyres were sold nearly brand new to another reefer.

There are currently 2 MP10s (max 1500 GPH) and 2 6015 Tunze (475 GPH) in the 250. That tank has 4 powerheads due to dead spots caused by the rock scape. The MP10s are running at less than 20% and the flow with 4 powerheads is still plenty for SPS. There is almost too much flow for the duncan coral or I would increase the GPH. There were Nero 5s in there before the Tunze and those worked great, but the other half took them for another tank.

 

[coralfishreef]

I also had 2 MP40s (4500 GPH) in that tank before and my opinion was that they were wasted in the tank. I had to keep the % very low and there were still dead spots because of the rock scape.