180 Flow Design...thoughts?

[gothunder3022]

Hi all...I'm in the early stages of a 180 build, and thought I would solicite some opinions on my initial flow design. I'm intending to keep a mixed reef.

My tank has dual overflows (rear corners). I'm thinking about ~2000gph return pump (via twin 1" Sea Swirls), ~2000 gph closed loop spray bar, and two MP40W's. By my calculations, that would be ~10x turn over throught the sump/refugium, and ~10K gph when the MP40's are at peak speed (~6K gph at their slowest). So my flow would oscillate between approximately 33 to 57x.

The tank (acrylic) is not presently drilled, so I have all options open at the moment.

 

[lizardarm]

This is only my opinion, but I'd go with more through the spraybar. On a 180, 2000 gph might not be enough. Having the two Vortechs is going to make the biggest visible difference of the three things you're looking at.

 

[gothunder3022]

thanks for the feedback. How much more would you go with for the spraybar? And what size holes do you recommend?

I'm definitely high on the Vortech's...I have an MP10 in my NC28 and it rocks!

 

[lizardarm]

Kinda depends on the purpose of the spraybar, and how long it's going to be. If your going to be puting holes all over it to get "random" flow, I'd go with something down the lines of a Sequence Dart pump (3600ish gph). If the holes are going to be directed more downward and forward for clearing the bottom/ detritus suspension, then maybe the 2000gph pump would work. Again, just my opinion.

 

[lizardarm]

But, I should also add that I don't have a very high opinion on spraybars. They seem to be more hassle/colg prone than they're worth. It's just one more thing that is fairly deep down, behind rock and corals, at the back (hardest to reach) of the tank that is going to need an occasional scrubbing down to remove coraline buildup.

 

[Chichas01]

I'm running a spray bar CL with a eheim 1262 on my 80 gallon and here are my thoughts:

• Drill fewer holes than you think you will need. I ended up patching up half the holes I drilled.
• Expirement with different patterns (holes higher or lower than the one next to it) and test them out in your bathtub to see what gives the best flow.
• If it's along the bottom at the back of the tank, you should think about using some sort of support rack to get your rock off the substrate (acrylic rods drilled into the base rock will work). It doesn't need to be to high, just enough for flow to work its way around and under the rock. This also lets your clean up critters get under the rock as well.
• Don't glue the bar together in case you need to service it for some reason. I left the main sections of mine unglued for just this reason should I have some need to remove it without having to move all the rock around to get to it.

 

[gothunder3022]

Thank you both for the feedback!

I'm a bit on the fence with the spraybar...there seems to be a pretty even divide on the pro's and con's, as well as what people think about using them or not. Ultimately I'd like to minimize how many holes I drill in the tank to reduce failure points. Maybe I should put another 1 or 2 MP40W's on the back near the bottom...but that might be over kill, and definitely expensive!

As for the holes...I've been experimenting with a 60 gallon cube and a standard 75 gallon acyrlic that I'm using to cure rock. So far I like having the holes distributed in 3 directions on the front side (45 degrees up and forward, ~30 degrees down and forward, and some facing straight out towards the front). And then a few pointing to the rear.

For hole size I worked up a little calculation in excel, for a given hole size (like 7/32") I calculate the number of holes necessary to match the area of the pump outlet. Then increase or decrease the number depending on whether I want add or lower water velocity.

How often are you removing the spray bar on your 80gal for cleaning?

 

[DolphinLVR]

I will be doing a 180 tank here in the very near future. I will have my return and will be going with 2 MP40's and possibly a Tunze on the back wall for my flow.

 

[Chichas01]

How often are you removing the spray bar on your 80gal for cleaning?

Haven't removed it yet. It's only been running for about 4 months now and is pretty much covered in coraline already but the holes are still wide open.

I also run 2 MP20's for my main flow and will be upgrading them to MP40's in the future. I've left a good amount of space along the back of the tank and depending on how much better ths MP40's are with the flow I may remove the spray bar and modify my CL to run with a 2-3 1/4" loc-line sections pointing to each side of the tank behind the rock. So far I've seen no detritus collecting along the back and the spray bar has worked well.

 

[roscoe]

You will notice a dramatic difference once you upgrade your MP20 to the 40. I had the 20 before I upgraded to the 40 and boy what a difference an extra 1200gph makes.

 

[gothunder3022]

Haven't removed it yet. It's only been running for about 4 months now and is pretty much covered in coraline already but the holes are still wide open.

I also run 2 MP20's for my main flow and will be upgrading them to MP40's in the future. I've left a good amount of space along the back of the tank and depending on how much better ths MP40's are with the flow I may remove the spray bar and modify my CL to run with a 2-3 1/4" loc-line sections pointing to each side of the tank behind the rock. So far I've seen no detritus collecting along the back and the spray bar has worked well.

Since you already have them, have you considered running one or both of the MP20's from the rear, near the bottom and remove the CL completely (once the MP40's are in)?