How much water movement is too much?

[Emma1234]

Hi

I have a 50 gallon reef tank that has been up for about a year and a half.

I have mushrooms, candy cane, star, zoas, clove, hammer, acan, lobo, and leather corals. Those have all been in the tank for over a year and are doing well. However I recently added a plate coral that seems to be dying. I have a lot of rocks as I'm trying to create a rock wall type of look covered with coral. I left large cracks between and on the sides of my "rock wall" for water to flow around the rocks. And I also drilled holes and hollowed out some of the rocks so that water could flow through them. It was a DIY rock job. Truth told I drilled holes because it was taking forever for the cement to dry. Drilling the holes and hollowing out the rock sped up the drying of the cement.

I do a 10% water change every 1-2 weeks. I have a fairly large cleanup crew of snails, crabs, shrimp, brittle stars.

I have a 20 gallon sump.

My phophate levels range from 0-25ppb on the Hanna checker. I believe that they are OK. However I do get some algae. And when I clean the tank there seems to be a lot of detritus on the rocks. For this reason I added a new power head today.

Up to today my water flow was generated by one small power head attached to the side the tank. The return from the sump. A power head at the bottom behind the rocks. And a power head on top to generate water movement on the surface.

The power head I added today is a CNZ (brand name) 800 GPH waver maker power head (bought from Amazon for $13). I was surprised to see that it is much larger than my other power heads that I currently have in my tank. When I put it in the tank detritus flew all over the place like I had a snow globe. It has since settled down.

My question is: Is the 800 GPH too much for a 50 gallon tank or is it what I needed given a large amount of rock surface? In other words was that snow globe effect an indication that I needed more water flow or is it a sign that an 850GPH power head is too much for the 50 gallon tank and that I may be blasting the heck out of my corals?

Thanks very much!

 

[A1t2o]

That's only 16x per hour. I'm around 30-40 myself. Just redirect the flow so that it is more turbulent and not directed at your corals. I like it when my power heads are blasting at each other creating turbulent flow or one aimed at the glass on the other side of the tank. Just reposition to get equal flow to front and back of tank, or more to the back. LPS coral may not like the flow as much so place accordingly, but it is still good for the tank.

 

[username in use]

That's only 16x per hour. I'm around 30-40 myself.

Yeah, that's not too much at all. Id be shooting for higher. I've had tanks as high as 120x turnover and everything was happy.

 

[Emma1234]

Thanks! :lolspin:

 

[oh207]

There is no such thing as too much water movement. Unless your fish are hiding all the time and the corals are getting stripped to the skeleton.

 

[CStrickland]

That's only 16x per hour. I'm around 30-40 myself. Just redirect the flow so that it is more turbulent and not directed at your corals. I like it when my power heads are blasting at each other creating turbulent flow or one aimed at the glass on the other side of the tank. Just reposition to get equal flow to front and back of tank, or more to the back. LPS coral may not like the flow as much so place accordingly, but it is still good for the tank.

This.

You can absolutely have too much flow. If you look inside a hammer you can see that it is lots of fine plates of bone with fleshy polyps in between. Too much flow will drag the flesh along those sharp fins of bone and scratch it up, those scratches can get infected with brown jelly disease etc. Or the coral will recede to prevent that and die for starvation since it can't catch light or food without extending its tentacle things.

Pointing the ph at something like glass or rock to buffer the flow, or even tucking it behind your rocks can help spread it out so that your lps get the gentle fluffing they like without being injured.

PS I have those cheap 800s and I really like how you can just slide them off the pin where they attach to the glass and point them into nooks and crannies. I blow out my rocks this way each week before a water change. Just don't like attack the corals with it, aim for the spots in the rock were crap collects.

 

[kmbyrnes]