2 MP40w in my 75G, undertow is ripping my torch coral to shreds!

[kurfer]

All my corals seem fine, I have 2 mp40w (whoever said 2 at 75% is required for my tank is a god damned idiot, plain and simple). I have them set on reef crest (lowest possible setting, linked set to match speeds (white).

The undertow in my tank is insane to the point I don't know how to slow it down other than rip out $1000 worth of powerheads and put my kor's back in.

The biggest issue I have with these pumps is they don't cause ANY surface agitation and create undertow making it impossible for any small torch corals to exist in my tank without being ripped apart.

Even on the lowest setting it looks like a god damned tornado is hitting my torch.

[HurricaneSystem]

Shouldn't be a problem properly placed and down on one or two setting.

[Reefnub]

Place your vortechs higher. Sounds like you have them in the center or lower center part of the tank.

[Breadman03]

I have one at 100% on my 75 gallon. I would try running 2 at about 40% and tweak it from there. I forget what mode it is on, but it is the one that toggles to/from nutrient transport mode.

[kurfer]

I have mine at the lowest setting and the undertow is still insane.

I currently have them 2 inches below water level and have tried at 5 inches. Yellow setting, tried pulse also.

Just can't stop my torch corals from looking like a tornado is ravishing them.

I'll post a video tomorrow.

Middle of the tank is fine, top is good too. My toadstool and hammer corals mid way up are doing great.

[Dexters Reef]

I have two on my 75g @ 75% and I run lagoon mode (higher power than reef crest, but less fluctuation) and tidal swell and nutrient transport, and I have no issues with my torch or frogspawn.

What works for someone doesn't work for everyone. Why don't you just turn them down a little? If I turn mine down all the way there is almost no flow. You should be able to find somewhere on that dial that makes everyone happy

The wet side grill has a small solid area, is yours pointing up or down? If its up, it reduces surface agitation and increases undertow. So in your situation, try ensuring the flat sections are pointed towards the sandbed.

Good luck! Looking forward to the video!

[kurfer]

I've tried all speeds, can't seem to find a sweet spot. :(

[Dexters Reef]

Check out this video of my tank...I have a large 14+ head torch coral, thats been in this spot since I set up the tank. It started as 2-3 heads and rapidly grew. Its only several inches in front of my MP40 and loves the flow

http://reefcentral.com/forums/showthread.php?t=2312600

[kurfer]

great video, love the tank...what's that green coral (SPS?) on near the top in the middle?

[Dexters Reef]

If its the large Yellow / Green fuzzy one towards the top right (and next to my right side return nozzle) its a Sunset Millepora. Grew him from a 2" frag that started on the sandbed.

I'll keep an eye out for your video, I dont know how the coral can be thrashed around with these pumps on their lowest setting, but I would like to see what your talking about and assist if possible.

[Alex Y EcoTech]

kurfer,

If you you continue to experience issues with your Torch coral, l would recommend re-positioning your MP40wES so it's flow does not come in direct contact with your Torch.

[jduck]

I had 4 on my 90g cranked to 90%. If you don't like the flow downgrade to the mp10's

[scarface70706]

do not down grade to mp10s. they will not be effective at all with your size system and might have trouble with your glass thickness. IME with my 90g mixed reef i have 2 mp40wes set at about 50% anti sync reef crest. torch is loving it. i recommend moving your mp's up higher on the sides. could you post a picture pls so i can help assist you more.

[worm5406]

Can you take a picture of the front of the MP40 controller.

Need to see the dots and the color of the knob.

Maybe a video would be better. Show us the front and then pan to show us the flow pattern in the tank.

Thanks!

[Ranger Daryl]

I had 2 mp40's in a 3' 65 gallon with no problems. No that I upgraded to a 4' 90, i'm planning to get a mp10 for the back.

[kurfer]

Well, I managed to fix the rapid undertow issues but making sure the plastic wall of the grill was facing down on both ends of the tank ( thanks for suggestions ). My flow is now calmed down for my torch but he still doesn't want to come out and play :(

Here is a video I did earlier to show the flow:

http://www.youtube.com/watch?v=whIhxty4DyY&hd=1

[Eastamherstbias]

by the video it just looks like you still have a ton/too much flow. Mine resembles a gentle breeze. Scale everything back 30% for 3 days and see if life emerges.

[bmullikin1]

Could you move 1 mp40 to the back of the same side you have it on now

[Eastamherstbias]

Yeah this seems easily fixable.

[kurfer]

So maybe I should move the one on the left side to the back of the tank facing front?

[Eastamherstbias]

So maybe I should move the one on the left side to the back of the tank facing front?

Or you could just turn them down. I have tons of sps. I give them enough flow to see a twitch, not like they are in a washing machine.

Turn down for three days and see how the corals respond.