flow and SPS

[E46er]

I have had a mixed reef for 8-9 years and have always wanted to go full SPS and had lost interest in it basically so I decided I better do it now or shut it down. currently I have completly cleaned out my DT and sump and vacuumed it totally clean Ive got my existing LR in my sump and my fish are swimming around happily. Ive built a couple rock structures that are currently cooking in a rubbermaid so I dont have any ammonia nitrate or phos go into the DT. I will try and post a picture but not sure how to do it from my phone. anyways one is a large arch with a few ledges and the other is a pillar. When they are done Im going to build another pillar out of my current LR and the rest can stay in the sump.

the rock will go pillar left piller center arch right. undecided if gonna go with bigger crushed coral sand or black sand. Ive tried bare bottom and cant get past the look, and sugar sand is all over the place. the archway will be slightly off square from the tank im think maybe 3-4"

my question is my DT is a 120G 4x2x2 and I have a snapper return also running carbon and GFO reactors and 2 jaebo RW8 power heads. on the sides facing each other my tank is drilled and piped for a closed loop (1 outlet through the back and 3 over the top) which had another snapper hooked up to it but the puump crapped out and I never bothered to replace it.
will my current flow be enough for a full SPS tank that I would consider fairly open planned?

option 1) flow is ok as it is.
option 2) add a 3rd RW8 (back wall?)
option 3) replace snapper pump on the CL this option is 3.5 times the cost and 5 times the power consumption of option 2

 

[E46er]

Beer can for size comparison.... OK it was to help.

any thoughts or opinions?

 

[CuzzA]

With those two powerheads and the open aquascape you'll be fine with option 1. At least until you have full blown colonies acting like sails. Then maybe at that time you add option 2 or 3.

 

[E46er]

ok thanks! but 135 views and no one else has an opinion on if thats adaquate flow or the rock structure?

 

[hart24601]

Fwiw I run a gyre 150 100% constant and 2 mp40qd also 100% constant on my sps dominate reef along with the return and I wouldn't mind some more flow. My tank is 120, 4x2x2. I think that's over 100x so I would personally add more. So option 2 if not yet another rw8 too.

 

[Perth_reefer]

I don't know anything about RW8s but on my 150G SPS dominated reef I have 4 MP40s and 2 Xaqua XinOuts, that equates to about 19500 gallons/hour flow, about 13x tank turnover per hour at max rate.

 

[joshky]

I would add two more RW8's and run them on lower speeds if needed while the SPS are frags, as they mature into colonies you will be thankful you have the ability to ramp them up. You can add on later, but I think two RW8's in a 120g is pushing it, my brother has two in a 80g and honestly if he wasn't trying to get out of the hobby for now I would be pushing him to get more flow because it's simply not enough. He has a very open aquascape, I think his tank dimensions are something like 42x24x18? I don't recall.

 

[E46er]

i keep the rw8s on the random mode so they do ramp up to 100% (2100gph)

I can order 2 more no problem where would you guys place them on my awesome paint drawings here.

Im thinking 1,2,9,10
or 1,2,5,7 with 5,7 being about 1/3 the way up from the bottom since my drawing isnt exactly to scale.

 

[joshky]

I would try two on the back panel, possibly option #6 and #7, and the other two on the side panels at option #9 and #10. I would keep the side panel powerheads pointed at each other and above the rock work so it's not stopping the flow. Eventually your corals will stop the flow, but that's when you up your speed or add more....

 

[joshky]

Flow is something you have to play to get right, so just tinker until you're happy.

 

[E46er]

:

Flow is something you have to play to get right, so just tinker until you're happy.

Of course. Mainly just looking for the best pace to start.

 

[Perth_reefer]

:

Of course. Mainly just looking for the best pace to start.

If you do an internet search for SPS tank flow rates you get a variety of answers, the lowest answer seems to be around 60x volume turnover per hour, up to about 90x. My system is 130x (my previous post should have said 130x not 13x) but I don't run my MP40s at full power. So you could say you're looking for an average of 75x with a minimum of 60x.
I'm not sure what your water volume is but with a sump and taking off rock work I'd have a vague guess at around 100G, if I've read it right one RW8 has a maximum turnover of 2000G per hour, so with two at full power you're running 4000G per hour, so 40x turnover, you could add a bit more on for your return pump - water head pressure loss. Personally I'd add a bit more for a full SPS dominated tank.

 

[Cosmojo]

What did you use to hold your structure together?

 

[Isaacs55]

I would definitely add a 3rd RW8 to your system. the more flow the better with sps.
I have 1 RW8 in my 10 gallon nano reef but its on the lowest setting. 4 would be best in my oppinion so you can dial the flow down if you need to.
or maybe get some RW15s

 

[E46er]

If you do an internet search for SPS tank flow rates you get a variety of answers, the lowest answer seems to be around 60x volume turnover per hour, up to about 90x. My system is 130x (my previous post should have said 130x not 13x) but I don't run my MP40s at full power. So you could say you're looking for an average of 75x with a minimum of 60x.
I'm not sure what your water volume is but with a sump and taking off rock work I'd have a vague guess at around 100G, if I've read it right one RW8 has a maximum turnover of 2000G per hour, so with two at full power you're running 4000G per hour, so 40x turnover, you could add a bit more on for your return pump - water head pressure loss. Personally I'd add a bit more for a full SPS dominated tank.

I know what searches seem to bring up for turnover but those numbers havent really changed since I started my first reef and rock was just stacked against the back wall with constant narrow flow power heads and now minimal rockwork in DT and random wide spead powerheads I was just wondering if numbers had changed. i figure the snapper does around 1300 after head pressure and the reactors its a little more than I wanted but it used to feed a fuge in my sump as well but when my sump cracked I ditched the fuge for a larger return section.
id also estimate your 100 G guess is pretty close in the DT as well. Ill order a few more RW8s when I get home tonight.

What did you use to hold your structure together?

epoxy and silicone. I know it doesnt look great right now but I wanted it solid enough that nothing in the tank (fish urchins snails) or me by accident cleaning or mounting frags would dislodge it and have it go crashing down. Im planning to not really even be able to see the rock so Im not worried about it standing out.

I would definitely add a 3rd RW8 to your system. the more flow the better with sps.
I have 1 RW8 in my 10 gallon nano reef but its on the lowest setting. 4 would be best in my oppinion so you can dial the flow down if you need to.
or maybe get some RW15s

everything Ive read says the rw15s are excessive in a 4' tank and Ive always been a believer of less flow in more locations than tons of flow from 1 spot. my return has 4 outets and my CL had 7. I have the rw8s on random mode. the waves surge in my overflows too much and I didnt dial the speed down since i knew I was on the low end of the req flow, and its annoying. Im going to order 2 more RW8s tonight.

if an upgrade isnt in the near future just out of curiousity why put such a big powerhead in such a small tank turned to lowest setting when an rw4 footprint is smaller, quite a bit cheeper and more useable?

 

[Cosmojo]

Oh who cares what it looks like now, that is quickly going to be covered up. GREAT looking rock work.

 

[Art13]

Well, i have a 90g 4 foot tank with a wp40 and rw8, i still want to add an rw-4 as i still need a bit more flow up top, its a harder balance and i try to keep low flow areas for some lps and softies, if i had only sps, i would like to have at least three rw-8s.

 

[Art13]

BTW, rock on the left, can we name that "Phallus Island"? Sorry, couldn't help myself, i like the rock work, it will be nice and open, i like the ledges. that left island though is my new favorite.

 

[E46er]

Oh who cares what it looks like now, that is quickly going to be covered up. GREAT looking rock work.

Thanks! I'm not very artistic or creative so it was the best I could come up with but always value other peoples opinions

BTW, rock on the left, can we name that "Phallus Island"? Sorry, couldn't help myself, i like the rock work, it will be nice and open, i like the ledges. that left island though is my new favorite.

I was actually surprised no one else commented on thst. I noticed it the day after I did it when the epoxy hadhardened.

Anyways I ordered 2 more RW8sthis morning before I left for Whistler.