Flow discussion

[crpeck]

My quest to replace my Mag pump with a restart problem has turned into a major research project that is making me nuts. It's hard to separate new information based on hard facts from fads and trends that have no basis.

My 55 gal tank was set up July 4th, 2003. Everything I read and was told about flow was "more is better". My drain is BIG and my return is geared to handle pumps around 1,000 gph or so (before head loss). My tank was originally set up with a Mag 9.5, which after head loss was probably getting 10 -12X or so turnover. That pump had problems and only a Mag 7 was in stock and that's what's been running the last 3 years. I started searching for pumps with the idea that I should increase my flow back up to around the Mag 9.5 level to get what was originally recommended for my tank under the theory of trying to get the most flow through my sump that my plumbing can handle.

Now, I find that the current thought is to drop the flow through the sump down to 3 - 5X and get water turnover through lower wattage/higher efficiency power heads. The theory is that skimmers in the sump benefit by having more water contact time with slower flow. Also, they say high sump turnover is uneccessary and an inferior method of creating flow with the new generation of powerheads like the Tunzes and such that have a wider path of flow that can be directed as needed to give the most turbulence/flow with the least power use. Proponents of this claim: better skimmer performance, electricity savings, quieter operation, and better refugium pod survival for those with sump based refugiums.

Others still claim that the more water run by their skimmer and filtration the better and that turnover through the sump should be a fast as it can handle. Another argument for this theory is that excessive power heads in the tank are ugly and unnatural looking and they don't want to rely on powerheads all over the place.

I suppose one key part of the argument is whether or not you have a closed loop on the tank. If so, then you probably could get away with lowering your exchange through the sump and keep a lot of flow without ugly powerheads. I don't want to get distracted by all the possibilities for getting flow in the tank. I don't have a closed loop and can't really plumb one the way my tank is set up. I'd really like to drill the question down to what the optimal flow through the sump is ..... high or low?

I've tried 2 1,000 gpg pumps that both were bad (1 noisy and the other one leaks) so am back to square one in deciding which pump to buy.

Help me please oh WTMRAC reef gurus.

[Codeman00]

It's crazy that there are so many ways to skin a cat when it comes to your questions. I ran into the same thing when I was designing my tank system.

I for one don't like to see powerheads in a tank at all and didn't want to deal with faulty suction cups, etc like I had heard about from my friends. So I went the closed loop manifold route which worked out, but could have been better. I had about 20x turnover total and split my closed loop up over 5-6 different nozzles of varying size. I was kind of happy with the set up but I didn't get the random flow that i would have liked...it seemed like it was tough to get flow everywhere and where I did, it was one directional. I would advise talking to Richard about his setup because it seems like he would only have a few outlets on his closed loop and his tank would swirl like crazy. I liked his setup better than mine after it was all said and done. I guess this is just supplemental info and doesn't really answer your questions.

There's probably something to be said for the tunze equipment but I have never used it, so I can't really comment on it.

I would advise slow flowing through your sump if there is a refugium inline, but a little faster flowing if you don't have a refugium. But then again, everyone does it different ways and has success.

As far as pumps..do you have a list of choices? I can comment on the Panworld pumps if you are considering one of those.

[scarson61]

I wanted los of water flow for my SPS and I've tried the Tunze which worked very well but still had a bit too much linear flow. I bought 2 Hydor Koralia powerheads after reading about them and I love them! Tons of flow and have a very random/chaotic flow. For the price ($100 for 2 of the # 4 @1200 GPH) it works like a charm on my 75 also they are magnetic mounted which I love.
http://archive.reefcentral.com/forum...hreadid=983152
Sanford

[crpeck]

Thanks, guys

I've heard great things about the Panworlds and if I had room for an external designed pump it would be a strong choice. I read that the engineer at Panworld was one of the designers at Iwaki and that the Panworld has some design characteristics superior to the Iwaki for less $$. Have a little cabinet nearly full of sump and don't have room for a big pump.

Thanks for the link on the Hydors, Sanford. I'll check that out.

Right now I have 2 Powersweeps in the back (yes ... I know they're crap, but they're the cheapest way to get rotating flow other than hydor adaptors which quit on me faster than the powersweeps). And I have two maxijets on a wavemaker in the fron corners. I don't mind the look of a couple of powerheads in the back corner, but I really do hate having the powerheads in the front.

Sanford, do you have those hydors on any kind of controller or do you run them full time?

[southernstang00]

Can you have too much flow in a tank?

[Codeman00]

I guess the answer is yes...but you want to take into consideration the inhabitants in your tank. If you are running a tank with all softies then you don't need over 20X flow and probably 15X would do. Just trying to put a new unattached mushroom in the tank will be futile due to it free floating around in the high flow. With SPS, there are some people out there that go up to crazy flows such as 50x. Many of those guys end up with bare bottom tanks though since the flow is so strong that nothing stays in place. But it grows corals.

Typically 20-30x good for mixed tank.

[crpeck]

How much total flow in the tank is a separate issue.

My issue is whether to get as much flow as I can through my sump via the return pump to minimize the use of power heads in the tank or to go with a low flow return through the sump and get my flow through power heads.

I know I can use anything from maxijets to tunzes to get flow in my tank. I'm trying to figure out how much flow I want running through my sump and return.

If its not detrimental to my skimmer or filtration efficiency, I'd like to get as much as I can through my return and minimize the need for in tank power heads.

If a big return pump is creating unecessary noise, power usage and cutting down on my skimmer's ability to work, then I should get a smaller return pump and find the least ugly, intrusive powerheads to put in the main tank.

I feel like I'm starting to answer my own question. I just wonder about this skimmer thing. I have the small Tunze skimmer in the middle chamber of one of the old U.S. Aquarium sumps that was built for bio balls. The skimmer's manual does say that too much turbulence around the skimmer will cut down on it's efficiency. But since the water runs over a baffle into that chamber, it's not being subjected to the drain flow. And does fast flow = turbulence? I think its two different things.

[joeycadre]

i'm really enjoying the dart that i have on the closed loop of my new 90 gallon. when i first ran it it looked like it was way too much flow but after a week i have great pe from my sps corals and my chevron loves to play in the currents. of course i don't have much rock work in it right now but all in all the 3600 gallon per hour pump is great. i do have it cranked back a bit with a ball valve but that just gives me more flow to play with.

also i have a 1" sea swirl on one of the loop returns and it does amazingly well for randomizing the current.

and another plus is that the thing is virtually silent. you might want to try a reflo snapper. i think they run at 2500 gph or so but you can always reduce that with a valve. these pumps actually run better supposedly when the flow is restricted a bit, more enegery efficient.

[cschumaker]

Take a look at this Cathy, it has made me reconsider the flow in my display. It shows that the tank turnover numbers so popular right now may not be as important as people think, putting more stress on the type of flow.
Flow article

another

another

Well, the whole series of 5 is interesting to read but these have the best information. =) Maybe they will help you decide what kind of flow you want in your tank.

As far as sump flow goes, I have macro in mine so I figured contact time was important but I think I may put a powerhead into increase gas exchange.

[sperry]

Just my .02 but I would think if you just have a sump higher flow through it wouldn't be a bad thing as long as your skimmer isn't running out of water or picking up a bunch of bubbles. If you have a fuge in line you would want slower flow.

[southernstang00]

Originally posted by Codeman00
I guess the answer is yes...but you want to take into consideration the inhabitants in your tank. If you are running a tank with all softies then you don't need over 20X flow and probably 15X would do. Just trying to put a new unattached mushroom in the tank will be futile due to it free floating around in the high flow. With SPS, there are some people out there that go up to crazy flows such as 50x. Many of those guys end up with bare bottom tanks though since the flow is so strong that nothing stays in place. But it grows corals.

Typically 20-30x good for mixed tank.

ohok, well I was just wondering and since it was about flow in this thread but CRpeck didn't mean to hijack the thread just had one question and it was answered in one answer...

[crpeck]

Thanks, Charley for the article links. Excellent info.

No wonder this hobby becomes addictive. The more you learn from every tank makes you want to do another. How many of us say to ourselves,

"Now that I know what I do now, I could make the next tank sooooooooo much better ........."

So has anyone we know built a true gyre tank? That is really a cool idea. You could hide all the powerheads behind the divider and put your pumps on timer to change the total flow on the tank back and forth like waves in the ocean.

My current tank is pretty limited in options. I'm getting closer to a conclusion.

Sanford, those Hydors do look good and cost so much less than the Tunze. Thanks.

Thanks all for your help.