Tank system turnover time

[makinwaveshhi]

Hello,

Just wondering how many times (per hour) my main pump should be turning over the water in my system?? info: 55 gal reef, 35 gal fuge/sump. There's got to be a good guideline for a healthy reef to follow, but I've forgotten how to do the calculations.

Thank you for the help.

 

[kevin]

First, before I will be able to help you out, I need to know what type of coral do you plan on keeping. It makes a big difference if you are trying to keep SPS vs softies, etc.

Thanks

 

[makinwaveshhi]

Thanks. I 've got softies, lots of em. But, please explain both the differences anyway. It'd be nice to know some of the whys and what ifs for the future. How much cycle (GPH) for softies and how much for SPS?

Thanks again.

 

[mojo]

Actually, I'd say the same for either- maybe 5-10x per hour is all that's really needed. Moving water through the sump faster doesn't clean it any faster. You could honestly probably have a great reef even at 1x per hour, but no one wants to try...

 

[xyzpdq0121]

mojo;29388 wrote: Actually, I'd say the same for either- maybe 5-10x per hour is all that's really needed. Moving water through the sump faster doesn't clean it any faster. You could honestly probably have a great reef even at 1x per hour, but no one wants to try...

I agree here... 5 x per hour is a good number... Too much more then that and you limit the contact time with your skimmer and your fuge...

 

[kwl1763]

Yep I agree. I actualy use 2x. Anything between 2-10 wil work. more is not better here as you can have microbubble issues, skimmer issues, etc as others have mentioned. You obviously need supplemental in tank flow. that is very dependent on what you want to keep.

 

[george]

My 25g is running about 3-4x (probably closer to 3x). I'll be using the same pump a bit wider open, but not much for my 60.

However, as mentioned, you need to get movement in your tank. For that I have a bit over 1400 gph whipping things around. I'll probably leave that for the 60 to give my mandarin a break.

 

[makinwaveshhi]

kwl1763;29420 wrote: Yep I agree. I actualy use 2x. Anything between 2-10 wil work. more is not better here as you can have microbubble issues, skimmer issues, etc as others have mentioned. You obviously need supplemental in tank flow. that is very dependent on what you want to keep.

YOU ALL ROCK!

Alright, that makes PERFECT sense! (kinda =) ) So, that's why I have a butt load of microbubbles in the tank, and can't get rid of all the algae that they are creating!!! Algae, algae, algae!! I've been fighting it for 2 years, and losing too. Sweet info! I was told that the faster I get the tank cycling the cleaner it will be. So this is incorrect? Well, that explains all the microbubbles, and hence all the algae! You've answered two of my questions. Thank you!

But, I have two more for all and any that can help--> One along the same lines:

1) So to get this straight...Tank turnover is not the major concern here, but the circulation in the Main tank is, right? More is better in the main tank, of course within reason. You don't want to creating a hurricane for your corals. Is this assumption correct?

My second question may have to go on a separate thread, not sure.

My Tank 55 gal, sump/fuge 35 gal approx.
2) Alright I have a Blueline 40 HD External Water Pump that is my return (main) pump. Specs: Approx HEAD now running on pump 7'Model40 HDMax Head 21' MAX HEAD Flow 790gph @ 0' In3/4" MPTOut3/4" MPTWatts120 WATTS Pressure RatedYes
DriveMagnetic
It's a great, cool, quiet pump...but maybe "a bit" too powerful. If course I have it turned way down on the output with a ball valve. But it's still making lots of microbubbles. I checked the seals & teflon tape, and they seem fine! I still think it's running too fast(gph).

Here's the question: I want to move the pump downstairs and increase the head to approx 14'. Therefore decreasing the pumps power and GPH! But, what would be the effects (<u>ON BOTH PUMP's EFFECIENCY, AND THE WATER PRESSURE AT THE OUTPUT INTO THE MAIN TANK</u>) of plumbing it with <u>1/2</u>", instead of <u>3/4</u>"? In other words which size should I use, that will still give me plenty of power to cycle the tank, and also GET RID OF THESE ACURSED MICROBUBBLES.

I hope you followed this, well enough to help me out. Once again thank you very much for the info.
K

 

[wbholwell]

Here's my two cents: If you move your pump downstairs your effeciency will be the same if your flow rate is the same- you're just finding another way to slow down the flow rate. I do, however, think that a large head is a better way to do it than a ball valve b/c the valve creates turbulence that could be introducing microbubble into the line (if it's not completely air-tight.) I wouldn't recommend going with a smaller diameter return, though. You want to keep the flow laminar.

 

[wbholwell]

One more thing- 3/4" seems small for the input. Does the pump have a 3/4" input as standard, or do you have it stepped down?

 

[wbholwell]

Ok, found out that 3/4" is standard for the pumps inlet & outlet. And water pressure will be greatest right after the pump, and will be the same in both scenarios assuming the flow rate is the same.Only with the ball valve you have a sharp decrease in pressure after the valve.

Are there any bubbles in your sump/fuge before the pump's intake?

 

[sammy33]

makinwaveshhi;29454 wrote:
1) So to get this straight...Tank turnover is not the major concern here, but the circulation in the Main tank is, right? More is better in the main tank, of course within reason. You don't want to creating a hurricane for your corals. Is this assumption correct?

K

The rule of thumb I use for sump returns is 3-5 times the display volume per hour through the sump or no more than 2-3 times the feed rate of your skimmer. Then for display flow for powerheads or a closed loop I try to target 10-20 times the display volume per hour or as much flow as I can get without blowing the sand off the bottom. For a 55 gallon sump return around 275 GPH would be plenty. Then an additional 550 to 1100 GPH in the display for circulation from powerheads or a closed loop.

Note that this still depends somewhat on your corals. What corals are you keeping?

makinwaveshhi;29454 wrote:

Here's the question: I want to move the pump downstairs and increase the head to approx 14'. Therefore decreasing the pumps power and GPH! But, what would be the effects (<u>ON BOTH PUMP's EFFECIENCY, AND THE WATER PRESSURE AT THE OUTPUT INTO THE MAIN TANK</u>) of plumbing it with <u>1/2</u>", instead of <u>3/4</u>"? In other words which size should I use, that will still give me plenty of power to cycle the tank, and also GET RID OF THESE ACURSED MICROBUBBLES.

K

I would try to use the same size plumbing as the pump has on the output. Piping down to 1/2" may restrict it too much. I think you will like the reduced flow speed through your sump and will likely see a decrease in micro bubbles.

 

[FutureInterest]

makinwaveshhi;29454 wrote: YOU ALL ROCK!

Alright, that makes PERFECT sense! (kinda =) ) So, that's why I have a butt load of microbubbles in the tank, and can't get rid of all the algae that they are creating!!! Algae, algae, algae!! I've been fighting it for 2 years, and losing too. Sweet info! I was told that the faster I get the tank cycling the cleaner it will be. So this is incorrect? Well, that explains all the microbubbles, and hence all the algae! You've answered two of my questions. Thank you!

Not sure how microbubbles relate to algae... I honestly don't think they're related. Getting your algae under control will be a seperate issue .

Anyways, there are about 3 major causes of microbubbles, I think you should try to address the microbubbles before moving your whole plumbing down a floor... If you can't fix this now, you're going to be pissed when you plumb that setup 10' lower and still have microbubbles. Well the 3 major causes that you need to focus on are: air seeping into the pipes; random bubbles entering the pump due to the return/skimmer; and finally cavitation.

The first one is easy to deal with... get some silicone and silicone up all the joints in your pvc. Just put a nice thick layer of it around all your pvc connection points. I saw that you used teflon tape which is good, but its not as bulletproof as say pvc glue with silicone around the outside of the joints.

The next microbubble cause is easily dealt with by using effective baffles or a filtersock. Personally, I use both... a filter sock on the return and most everyone uses baffles in the sump. Sometimes your flow can be so great in the sump that bubbles are flying right through the baffles... You can use a large sponge at this point to physically limit the bubbles. Keep in mind that it will need regular cleaning or it will become a nitrate factory.

Finally, there's cavitation. This is essentially where air bubbles are pulled out of the water due to low pressure areas. Basically, the low pressure is causing the water to "boil" such that gases are released into the water flow. The best way to deal with this is proper planning to streamline your plumbing and making sure its as consistent as possible. Things like 90 degree turns, various valves or changes in diamter of piping can cause cavitation. I'm anal as hell so I even went so far as to sand the inner portions of my pvc joints to reduce turbulence and use flexible pvc for the majority of my plumbing.

Good luck.

 

[xyzpdq0121]

Jin and Sam make great points here. I think you are dealing withalot of issues here. I say instead of trying to limit a pump that is too powerful to "fix" a job, get a new pump. On my 55G I use a CAP 2200 pump that I think is rated 400gph, maybe not even that much. Calculate in head loss and you are getting more like 325gph. It works nicely for my set up. I run my tank circulation off a closed-loop that used to run a Mag 9.5 (950gph) and looks like I am going to settle on the Mag 18 to get the job sone. (I tried the Mag 36 thinking more is better, believe me, it is not! Goby guts are hard to clean off the glass! )

 

[johnqx4]

FutureInterest;29505 wrote: I'm anal as hell so I even went so far as to sand the inner portions of my pvc joints to reduce turbulence.

Ya Think :thumbs:

 

[kh971]

One of the downfalls of not having a large turnover through your sump, is that deitrus will settle on your sand bed and in other portions of the tank. Powerheads can only blow it around for so long before it will find calm water and settle. Having a larger turnover thru your sump, helps pick up waste faster and send it to your sump and skimmer, becasue of an upward flow from the base of your tank to the overflows and to your skimmer. I know this does not work perfectly, but a good theory to replicate. A larger skimmer with a higher than normal turnover rate is necessary in this situation also, since water is passing by it quicker, so the processing rate of the skimmer must be larger than what is recommended for your tank. The more flow in the tank and less dead spots and a high turnover rate=a cleaner tank.My 2 cents.

 

[kh971]

I know alot of people who have turnover rates of up to 10+ times an hour, it also eliminates the uses of powerheads and the sight of the them. I actually have 2000 gph going through my 100 gallon sump and refugium, that is 24 inches wide and the laminar flow is not bad at all.

 

[makinwaveshhi]

wbholwell;29465 wrote: Ok, found out that 3/4" is standard for the pumps inlet & outlet. And water pressure will be greatest right after the pump, and will be the same in both scenarios assuming the flow rate is the same.Only with the ball valve you have a sharp decrease in pressure after the valve.

Are there any bubbles in your sump/fuge before the pump's intake?

No bubbles what so ever, the 3 baffles in my fuge/sump take care of that. I'm thinking that it's the pressure build up coming from too strong flow (gph) out of the pump. And that a larger head height will help me fix this. I turned the ball valve off a little more (slowing the turnover flow) and a majority of the larger bubbles went away. Now they are VERY small coming out the return...Kinda "chopped up" to make what looks like a mist coming out of the return pipe into the tank. Looks like what maybe the needlewheel does in the pump impeller of my skimmer but way finer bubbles. But I will say that my tank has already improved (I mean the way all the critters look now with the change in ball valve setting).

So I think I'll move the pump downstairs adding to a 7' head, 7 more feet...making the total head somewhere around 14'. I think this will help a lot with the pressure and microbubbles...and I'll always have the ball valve if it's still too much. But I'm unsure whether to use 3/4" PVC piping or the 3/4" white PVC flex-tubing for the new hook-up??! Does any of this make any sense? =) Am I on the right track?

Hope this answers some of your questions.

Thanks!!

 

[makinwaveshhi]

FutureInterest;29505 wrote: Not sure how microbubbles relate to algae... I honestly don't think they're related. Getting your algae under control will be a seperate issue .

Anyways, there are about 3 major causes of microbubbles, I think you should try to address the microbubbles before moving your whole plumbing down a floor... If you can't fix this now, you're going to be pissed when you plumb that setup 10' lower and still have microbubbles. Well the 3 major causes that you need to focus on are: air seeping into the pipes; random bubbles entering the pump due to the return/skimmer; and finally cavitation.

The first one is easy to deal with... get some silicone and silicone up all the joints in your pvc. Just put a nice thick layer of it around all your pvc connection points. I saw that you used teflon tape which is good, but its not as bulletproof as say pvc glue with silicone around the outside of the joints.

The next microbubble cause is easily dealt with by using effective baffles or a filtersock. Personally, I use both... a filter sock on the return and most everyone uses baffles in the sump. Sometimes your flow can be so great in the sump that bubbles are flying right through the baffles... You can use a large sponge at this point to physically limit the bubbles. Keep in mind that it will need regular cleaning or it will become a nitrate factory.

Finally, there's cavitation. This is essentially where air bubbles are pulled out of the water due to low pressure areas. Basically, the low pressure is causing the water to "boil" such that gases are released into the water flow. The best way to deal with this is proper planning to streamline your plumbing and making sure its as consistent as possible. Things like 90 degree turns, various valves or changes in diamter of piping can cause cavitation. I'm anal as hell so I even went so far as to sand the inner portions of my pvc joints to reduce turbulence and use flexible pvc for the majority of my plumbing.

Good luck.

Thanks!
The microbubbles somehow settle on all the rocks and then algae starts to grow rapidy...first green, then red, green hair algae. Even with many large water changes, the bubbles are still coming out the sump return into the tank. Therefore the algae returns just as fast as before scrubbing and the h2o changes. Confusing...so it must be the bubbles, cuz that's where a majority of the algae forms (where the bubbles settle) and begin to spread like wildfire across the tank.

1}Nice info about the silicone at pipe joints, I'll try that. Have you ever used teflon pipe compound (gooie, messy stuff) instead of teflon tape at threaded connections?

2}All good on the baffles in the sump there are no bubbles in the last chamber in the sump where the pump intake returns it back to the tank.

3}I think that it has a lot to do with your #3: Cavitation...I'll straighten out the piping, try and remove the 90's that are in it. And switch over to the flexible PVC. And with the powerful pump pressure that is being pushed through that ball valve there has to be some pressure air boiling with water that is entering the flow and causing all the fine, tiny bubbles.

Hope this makes sense, thanks for the help.

 

[makinwaveshhi]

Xyzpdq0121;29508 wrote: On my 55G I use a CAP 2200 pump that I think is rated 400gph, maybe not even that much. Calculate in head loss and you are getting more like 325gph. )

I'm thinkin' that your CAP2200 runs at more like 800gph @ 0 ft, not sure about the head height or how much your losing due to it.