Such a thing as too much flow?

Title says it. Is there such a thing as too much flow for fish? Lets say that I have a return pump, rated at 1000 GPH, and its pumping water crazily back into the display tank. A fish, clownfish or any kind of fish, swims by and the flow just blows it into the glass or onto the rocks or just somewhere else. Would that ever happen, or are fish strong enough to swim against big currents?

 

How big is the display tank? Keep in mind that a pump rated at 1000gal/hour is not actually pumping that into your tank. Any height that it has to pump up to in order to get to the tank will diminish its gal/hour. Also is the pump rated at 1000 gal/hour or is it a 1000 model of a certain type of pump?

The short answer to your question is yes, you can have to much flow, but when you reach that limit is up to the actual return flow (there are calculators for this online if you can do a little looking around), the size of your tank, what your tank is aimed at (fish, coral, if coral then what types?)

Sometimes fish like to ride the return flow current. My chromis are return flow surfing junkies;D If they really hate it then they will stay away.

 

You would be surprised at the amount of flow and strength of the water current associated by certain areas in reef biotopes. Flow is more of a concern for certain corals than that of fish!
It is best to reduce the laminar type flow and also diffuse the flow coming right out of the powerheads by positioning the heads to bank off the glass strategically for better disbursal to a greater part of your tank.

 

Thanks guys, the display tank is a regular 40gallon. The return line is probably about 2 1/2 feet from the sump to the tank. Well today I created a spray bar that is about 21" across the back of the tank spraying against the glass. As for corals, I am going to try beginner SPS corals and I've read that they need great flow for them to thrive.

Just one more quick off topic question. Is it normal for the raw shrimp that you dump into the tank for it to cycle to color up into an orange color like when shrimp is cooked? The temperature stays at 76-78 degrees F, and never exceeding that.

 

I couldn't tell you about the shrimp, but do you have fish in that tank while you are cycling? Also, a spray bar diminishes flow a lot.You are probably better off teeing off the return flow for two returns if you are that concerned about it. Is the pump a 1000 model or 1000gal/hour? Another thing make sure that when you say the height from the sump to display is 2.5 feet that you include the height of the sump that the water has to be pumped up. Your pump is at the bottom of your sump right?

 

There are no fish at all in the tank right now. Theres only a hitchhiker orange zoo that still opens up. The pump is rated at 1000 GPH and actually measuring my return, it is more like 4 feet (Sorry about the last post). The pump is also on the bottom of the sump but the tube that shoots water out is almost 3 inches above the pump. I tried the two separate return nozzles, but it was still too much. It just blew water onto the glass and that made the sand in the front move and water splash out. The spray bar is a lot better but it still kicks up sand in the front of the display. I guess i have to spread out the sand to the back leaving the area in the front not as high. I am just concerned about the sand disturbing a clam that I was planning to put there. Thank you for your quick responses

 

I've always heard GPH should be 10 x size of tank. I'm sure it depends on what's in it though.

 

You are correct, it depends on what is in it. Fish, corals, what type of corals (some like low flow, other moderate, and even others prefer high). The only way to know if the flow is too much is to know what the tank is aimed at in terms of goals.

 

i went through alot of different powerheads and place ments of them and corals, to get it to where i want it, and i am still not very happy with it

 

i used a 1200gph pump in my 55gallon and there was rocks blowing around the tank.i could'nt see them that well with all the sand lol.i went down to 700gph for the sump return and use powerheads to circulate the display tank evenly.