How much Flow and How much Light

[Dr. Reef]

Fellow Reefers.
This subject is brought up a lot in newbie section time and time again. There is no universal answer to these questions as many variables due to tank sizes, depth and heights and light fixtures used.
I will try to explain what I know over many yrs of keeping reef tanks.

Flow through sump:

Flow through the sump should be 5-15 times the volume of ur entire water body in an hour. This number has a lot of variables as well. This number depends on ur return pump and drain capacity along with what type of corals need to be kept in the reef.

Flow inside the Main Tank:

Flow of water inside the main tank matters as to which rate we try to grow a healthy reef. Flow consists of only water inside the main tank. Flow inside refers to capacity of return pump after head loss, closed loops capabilities and power heads used.
All these add up to make the flow inside the reef. Flow should be random not straight. meaning: directing the flow in a way that it either bounces off the walls or smashes against each others waves etc. causing a turbulence rather than a straight line of water wave.
A good estimate to shoot for is as follows:

Combined gallons per hour (gph) in a

Fish only Tank: 5-15 times the volume
Fish with soft corals: 15-20 times
Fish with soft and lps and sps: 20-30 times
Sps dominated: 45 times and up.

for example: 120gal tank with a return pump (mag 12) no close loop 2 maxi jets 1600gph
This tank has 800gph from mag 12 after head loss plus 2x 1600gph=3600
so a total of 4400 gph.

This example Tank is producing 36 times the flow thus putting is suitable for mixed reef maybe pushing few hardy sps corals. in order to get into the sps dominated status this tank will need another source of flow increasing it from 36 time to over 45 times.


Lights in a reef tank:

Lights have taken a new turn towards LEDS and they are getting cheap and more reliable than ever. Still a new technology but has already reached most reefers tanks.
Best policy to acclimate ur new arrivals to LED is to either:

1. Place them on the sand bed for 1 week then move them few inches up every week till u reach the final resting point. or
2. Decrease the lights to 30% and increase 1-3% per week till u reach the final intensity u prefer.
LED lights are best measured by PAR meter and I will give u a safe PAR rating to shoot for so u can grow ur corals happily.

Soft corals PAR: 175-275
LPS: 300-450
SPS: 500 plus

Again there are many variables in every tank and each tank is different. These guidelines are just a basic to consider in order to achieve a healthy flourishing reef. Please use ur own common sense and knowledge or ask here at RC and someone can help you in ur particular tank.

Good Luck and
Happy & Safe Reefing.

Thanks
Mike
The Reef Doctor.

Note: if i made a mistake or if u like to add on to something i missed please feel free to do so as the intended purpose is to educate the newbies.

 

[BlindZide]

If there isn't a sticky on this, then this should be so people like me an be directed here.

I have a question regarding the turnover rates you have listed. I did a 30x turnover in my 30g and it was a nightmare (2xMJ400 in laminar 500gph mode). It was like a tropical cyclone was inside my tank. No matter how I positioned the powerheads it was bad.

My question is how accurate are the GPH rates on the pumps themselves? Could it have been that it was mislabeled? I had to take one out to get my corals to open and be happy. Am I missing something?

 

[Cozwey]

+1 on the sticky

 

[Dr. Reef]

If there isn't a sticky on this, then this should be so people like me an be directed here.

I have a question regarding the turnover rates you have listed. I did a 30x turnover in my 30g and it was a nightmare (2xMJ400 in laminar 500gph mode). It was like a tropical cyclone was inside my tank. No matter how I positioned the powerheads it was bad.

My question is how accurate are the GPH rates on the pumps themselves? Could it have been that it was mislabeled? I had to take one out to get my corals to open and be happy. Am I missing something?

in a small tank 2 power head 500gph each will cause cyclones. but key is to keep a lot of flow for mixed reef as sps tends to like a lot of flow. u can keep a little less flow only difference will be the branching sps will have thinner stalks while with lots of flow will cause thicker trunks.

 

[BlindZide]

OK so that is why my Hydnophora, once I got the flow right, swelled up like 3 times the size he was? That is amazing. I was guessing that was the cause but I also changed salt around this time as well and didn't know if the added trace elements were to thank.

 

[Dr. Reef]

probably collection of both. lol atleast u have it right.

 

[Coral Head]

Fellow Reefers.
This subject is brought up a lot in newbie section time and time again. There is no universal answer to these questions as many variables due to tank sizes, depth and heights and light fixtures used.
I will try to explain what I know over many yrs of keeping reef tanks.

Flow through sump:

Flow through the sump should be 5-15 times the volume of ur entire water body in an hour. This number has a lot of variables as well. This number depends on ur return pump and drain capacity along with what type of corals need to be kept in the reef.

Flow inside the Main Tank:

Flow of water inside the main tank matters as to which rate we try to grow a healthy reef. Flow consists of only water inside the main tank. Flow inside refers to capacity of return pump after head loss, closed loops capabilities and power heads used.
All these add up to make the flow inside the reef. Flow should be random not straight. meaning: directing the flow in a way that it either bounces off the walls or smashes against each others waves etc. causing a turbulence rather than a straight line of water wave.
A good estimate to shoot for is as follows:

Combined gallons per hour (gph) in a

Fish only Tank: 5-15 times the volume
Fish with soft corals: 15-20 times
Fish with soft and lps and sps: 20-30 times
Sps dominated: 45 times and up.

for example: 120gal tank with a return pump (mag 12) no close loop 2 maxi jets 1600gph
This tank has 800gph from mag 12 after head loss plus 2x 1600gph=3600
so a total of 4400 gph.

This example Tank is producing 36 times the flow thus putting is suitable for mixed reef maybe pushing few hardy sps corals. in order to get into the sps dominated status this tank will need another source of flow increasing it from 36 time to over 45 times.


Lights in a reef tank:

Lights have taken a new turn towards LEDS and they are getting cheap and more reliable than ever. Still a new technology but has already reached most reefers tanks.
Best policy to acclimate ur new arrivals to LED is to either:

1. Place them on the sand bed for 1 week then move them few inches up every week till u reach the final resting point. or
2. Decrease the lights to 30% and increase 1-3% per week till u reach the final intensity u prefer.
LED lights are best measured by PAR meter and I will give u a safe PAR rating to shoot for so u can grow ur corals happily.

Soft corals PAR: 175-275
LPS: 300-450
SPS: 500 plus

Again there are many variables in every tank and each tank is different. These guidelines are just a basic to consider in order to achieve a healthy flourishing reef. Please use ur own common sense and knowledge or ask here at RC and someone can help you in ur particular tank.

Good Luck and
Happy & Safe Reefing.

Thanks
Mike
The Reef Doctor.

Note: if i made a mistake or if u like to add on to something i missed please feel free to do so as the intended purpose is to educate the newbies.

Great article, Mike. Can you address the photo period recommendations?

Thanks!
Rick

 

[Dr. Reef]

Photo Period:

For fish only system: Min 6 hrs to 8 hrs.
Reef systems: 6 to 8 hrs. best done with dawn and dusk feature and moon light.
Generally turn the actinics/blue lights on 1-2 hrs prior to main white lights and likewise after whites go off 1-2 hrs of blue/actinic light after.
moon lights all through out the nite.
I like white lights at full strength for 6 hrs min and actinics for 1 hour more prior and 1 hr after.

 

[FsuNole]

Lights in a reef tank:

Lights have taken a new turn towards LEDS and they are getting cheap and more reliable than ever. Still a new technology but has already reached most reefers tanks.
Best policy to acclimate ur new arrivals to LED is to either:

1. Place them on the sand bed for 1 week then move them few inches up every week till u reach the final resting point. or
2. Decrease the lights to 30% and increase 1-3% per week till u reach the final intensity u prefer.
LED lights are best measured by PAR meter and I will give u a safe PAR rating to shoot for so u can grow ur corals happily.

Soft corals PAR: 175-275
LPS: 300-450
SPS: 500 plus

Again there are many variables in every tank and each tank is different. These guidelines are just a basic to consider in order to achieve a healthy flourishing reef. Please use ur own common sense and knowledge or ask here at RC and someone can help you in ur particular tank.

Good Luck and
Happy & Safe Reefing.

Thanks
Mike
The Reef Doctor.

Note: if i made a mistake or if u like to add on to something i missed please feel free to do so as the intended purpose is to educate the newbies.

If you don't have a par meter and are using T5 lights is there anything you should go off as far as rule of thumb? For example I'm looking at a Quad with 156W total output. Would this be enough for a few LPS in a mainly FOWLR tank?

Great write up!

 

[Dr. Reef]

T5 quad bulbs in a tank with fish and live rock should be fine to grow softies and LPS. what size tank is it?

 

[wesside]

T5 quad bulbs in a tank with fish and live rock should be fine to grow softies and LPS. what size tank is it?

My tank is 36 long x 18 wide x 24 tall. Will that height require more than the quad T5 that you said would work for softies and LPS?

 

[Hokies83]

I have 55 ggallon got 900 Gpu return pump and a 1300 Gpu wave maker.

Wave maker is blowing onto the live rock return towards the top but both same direction.

I have another 1300 Gpu and a 800 typhoon wave maker when i put them on the other side it just makes a huge mess and all my fish just hide.

Should I leave it with out them or try putting one somewhere else?

I got a maxi jet 1200 im going to use as a power head only 300 Gpu what that be a better route?

Thx!

 

[jerpa]

My tank is 36 long x 18 wide x 24 tall. Will thatheightrequire more than thequad T5 that you said would work for softies and LPS?

You will need a fixture that incorporates individual reflector due to the 24" depth of your tank. 4 bulbs is enough if you position the more light hungry corals in the upper half of the aquarium. A 6 bulb fixture would allow you more flexibility with placement and bulb combinations though.

 

[Reef Frog]

Great post. I will add this to describe specifically how water flow affects various animals:

- Delivers planktonic food to coral polyps, feather dusters etc.
- Water abrasion helps old coral polyp cells "slough" off, assisting tissue regeneration.
- Good flow helps some pest algae from gaining a foothold. Especially applies to cyano.
- Good flow helps keep some pest populations like flatworms from getting out of control.
- Good flow from the sump & inside the tank promotes oxygen (and other gas) exchange.
- Good flow mixes all the water thoroughly, preventing eddies & dead pockets.
- Good flow promotes fast & complete dissolving of aquarium additives & prevents the precipitation of solids.
- Good flow can help keep detritus suspended longer after a tank cleaning, where it can be more completely removed by protein skimming & mechanical filtration.
- Good flow keeps many pump manufacturers in business selling some nice but expensive pumps. This also keeps aquarists from overspending on things like food, housing, beer etc.
- Many, but not all, fish thrive in currents as it replicates their natural environment.

 

[Reef noob_]

Any idea if a 36 watt t5 would be enough to grow soft corals and some Lps in a 10 gallon tank, or do I need more to grow mushrooms, star polyps, a couple zooanthids, a candy cane coral, an Xenia and a torch coral? Thanks in advance

 

[Dr. Reef]

is it a dual t5? if so u will get away with softies.

 

[Reef noob_]

It is a dual but I was also looking at a quad lamp with 72 watts that I think might be a bit better for the corals, or is that overkill?

 

[Dr. Reef]

It is a dual but I was also looking at a quad lamp with 72 watts that I think might be a bit better for the corals, or is that overkill?

well it could be for 10 gal tank but then again most quads have on/off switch and u can easily turn 2 off to make it a dual if you think 4 is a lot more than u need. but if you do decide to go with sps and some light demanding lps then quad will be better.

 

[Reef noob_]

Okay thanks so much for the quick replies! Would it be a problem to have too much light? Does that cause massive algae outbreaks as it does in freshwater or harm corals? Also I was planning on keeping mostly softies and a few Lps, but eventually maybe moving onto Sps and harder corals.

 

[Dr. Reef]

having too much light can cause algae blooms that is why we should limit the hours of light. with a quad fixture you can setup a dawn and dusk and limit main white light to 6 hrs per day. For softies dual light will work for sps and some lps you will need all the light.