Balanced flow

[ChuckG]

How do you know when to stop adding flow? I have a 75G with two MP40s on it and the rockwork is very open and conducive to flow throughout. Typically I'll let the pumps spin up in reefcrest or lagoon mode up to a max 90% total power which at that rate is a good amount of flow for a 75. I have them positioned to push a gyre around the tank.

The tank is and will continue to be predomiantly SPS oriented. The SPS seem to be OK with the flow as it is as they are growing doing OK. One of the problems is though that I can't keep the reef floor special grade sand to stuck to the middle of the tank. It all gets pushed to the sides and the tank winds up being half bare bottom over night.

The other problem is that realisticly I'd lke to have a couple LPS, maybe a clam in there to. For instance I picked up a nice multicolor frog spawn for some clowns to possibly take up residence in. I put this in one of the back corners in the least area of flow available and it is still getting beat to shreads.. popping off tenticles, stressed etc..

I need to find a balance. I guess for more of a mixed type environment yet still addresses the needs of the sps in the tank since they are in the majority. So how do you determine what is enough flow without going overboard?

 

[ChuckG]

Anyone have thoughts on how much flow is needed to keep SPS happy without kicking up the sandbed or thrashing LPS species?

 

[ebonline]

Don't know much about the MP40's (I use a closed loop) but as far as flow you want it to be more random and it sounds like you might be able to get by with just 1 MP40 on this tank. Is the flow adjustable on some type of controller with the MP40??? Maybe someone else will chime in...

As far as your sand maybe try a little larger sand size in the areas where it gets blown around. You IMO want some lower flow areas in the tank as well as there are several species of SPS and LPS that like and grow better in lower flow areas.

Don't know if this was any help.

 

[ChuckG]

Don't know much about the MP40's (I use a closed loop) but as far as flow you want it to be more random and it sounds like you might be able to get by with just 1 MP40 on this tank. Is the flow adjustable on some type of controller with the MP40??? Maybe someone else will chime in...

As far as your sand maybe try a little larger sand size in the areas where it gets blown around. You IMO want some lower flow areas in the tank as well as there are several species of SPS and LPS that like and grow better in lower flow areas.

Don't know if this was any help.

Thanks for the thoughts.. Flow with the vortech pumps is adjustable and can be configured to run randomly. I read some other similar threads found in a search and most answers suggest a flow rate that is some multiple of the display tanks volume. I read answers specifying a turnover rate for SPS that ranges from 30Xs to 90Xs the display tank volume.

I have been operating at about 75x turnover rate simply because I could and thought the sps species might appreciate it.. but I can't keep sand on the bottom. Two of these pumps are overkill for this tank and I bought them knowing I would be upgrading the display to at least a 150G in a years time. Reef flor special grade is a larger grain size by the way.

I guess my answer lies in adjusting the rate downward until the LPS looks somewhat comfortable and I can just barley keep sand in one spot. 100% in reefcrest random mode might be the ticket because it effectly runs on average at 60% the pumps flow potential which would be approx a 45x turnover rate.

Normally I wouldn't keep frogspawn in this tank but would like to see if the clowns will use it as a host. Eventually once I've upgraded displays it wil be replaced with a carpet anenome which should appreciate the higher flow rates we typically keep for SPS and all of this will be less of a problem.

 

[powderhound]

Do you have them running in anti sync or sync? I have 2 on my 75 also, and cant seem to keep the sand in the middle of the tank either. i found running them independently of each other on reefcrest seems to work the best. i alternate one at 50% the other at full and change them every couple of days.

 

[ChuckG]

I was mosly running them indepentant of each other as well because it seems to result in the most random flow patterns.

Right now I have them in anti-synch reefcrest mode with max power set at 90% and flow is on average much less agressive.