How much flow do I need for Mixed Reef tank?

+1 Exactly.

I only have 20x in my softie tank, and some still had to be placed in lower-flow areas.

 

Couldnt agree more. My xenia colony has expanded in a way that the outer edges have reached a high flow zone and my jasmine polyp has also grown up into a higher flow zone and look like they are being blown a little to much. Still open all the way and growing so I guess its ok but I wouldnt put more flow on them

The more PH you have the better but when it comes to a flow rate a 1500gph is not equal to 3 500gph PHs. Maybe they have the same flow, but intensity if dropped and if they bounce off each other right it makes more of a natural unpredicable flow rather than a linear flow. Thats why you never really palce a PH pointed right on a coral, it would rip its skin off over time. I will say though that flow is the hardest part in setting up the tank. Even after 8months I am always adjusted my PH to try and get the perfect flow, and every time I add new corals I need to watch and sometimes move a coral or adjsut a powerhead to make sure it gets what it needs while keeping others happy.

 

Not to be rude but I wouldn't contribute all the beautiful mixed reef tanks to luck. The only luck we get in this hobby is avoiding bad hitchhikers, finding good ones, and obtaining disease free specimens. Even with that a lot of time and energy goes into helping prevent bad luck. Mixed reefs are all about proper aquascaping with light and flow while placing corals where they can succeed. Trial and error to see what works and what doesnt and letting your tank and the inhabitants tell you what you need to do play a big role in yous success.

Also, I have heard it both ways with the softies and sps. Some sources say softies inhibant growth in sps chemically, as well as being able to over grow and shade them causing issues. I have also read where trimming xenia near an SPS seems to make their polyps extend as if they are feeding on the small particles. Either way, chemical warfare can be avoided with a good schedule of changing quality carbon.

 

Very good insight here guys. I really appreciate that.

PghSteeler, if you can find the article, that would be great.

 

I agree, many soft tissue corals will not tolerate much flow. Some of the best softie tanks I've seen have less than 10x-15x flow and do quite well.

I also don't think you need 50x flow for SPS. Althouh there can be benefits.

The thing that is missing here I think is that when you star mixing corals, the total flow doesn't actually matter as much as the water movement around a particular coral. 10x could be fine for SPS if the water movement is sufficienty higer than in other areas of the tank, so that they are able to "breath" and obtain "nutrients" fast enough to grow.

Likewise, you could have 100x turnover and have happy softies, if the bulk of the flow is in areas of the tank away from them.

As to softie chemicals, this is debatable. I think it is safe to say, most of the time people do not have issues mixing corals, that are attributable to chemicals. There my be exceptions, there may be cases were people want to explain what they don't understand etc.... If there are chemicals, flow and GAC filtration would expidite their removal and limit negative effects. If you don't have proper flow and filtration, you may have issues anyways.... When you start mixing corals, things do get more complicated and tricky though regardless of the exact reasons and different people will convince themselves that there are different explanations...

In all cases, there probably is a lot more going on than realized though.
For example, flow may inhibit or encourage algae growth, depending on the algae and flow. Algae may inhibit or encourage bacteria, which may inhibit or encorage coral growth, depending on which way the balance falls with regards to a number of other factors. The simpler and more homogeneous we keep our systems, the easier it is to achieve the desired balance.

 

Im not sure where it was byt the link in Mr Bills sig is a good read and mentions what I was getting at
Advances

 

One point that didn't get mentioned is that the chemicals produced by each species of leather affects all other corals, including other species of leathers. IOW, when one has a softie tank with mixed leathers (as I do), the situation is the same as a mixed reef. SPS corals are not the only ones threatened. But as PghSteeler and m2434 mentioned, a good quality carbon (GAC) will remove the toxins before they can cause harm.

 

Thank you for everyone's knowledge. I appreciate it. Very informative.