Need help with flow - concerned about Nitrates

[jill]

I'm wondering if I could do a better job with flow.
My big tank is 250 g acrylic with dimensions 64" l by 24" wide and 31" high. Its got three sides exposed - I've attached a picture.
Currently I have a Coralife 1740 return pump with 6 return sprays in through the bottom of the tank. Sorry if my if I don't have my jargon right but I hope I'm getting my point across.
I have one Koralia #8 right under the weir wall and another #4 nearer the bottom on the other side of the rock work.
I'm concerned that my about my nitrate level. Although my API tests say I have 0, my Elos test (which I trust more) say I consistantly have about 10 ppm. I do 30 g water changes once a week and am pretty careful with the food. I have an SWC Xtreme Cone 250S and the following fish:
Purple tang (4")
Yellow headed gobi (4")
Lemon Peel (3")
Coral Beauty (3")
Majestic Angel (2")
2 Heniochus (1 1/2")
Orchid Dottyback (1")
Royal Gramma (1 1/2")
Purple Firefish (1 1/2")
Valentini Puffer 3"
Maroon Clown 2 1/2 "
Midas Blenny 4"
Blue Damsel 2"

So, do you think that I have enough flow? If not does anyone have any ideas on what I could do to improve it?

 

[ReefJunkie]

IMO that would not be enough flow, but then it appears that you do not have many corals in your tank yet. A vortech MP40 on each end of your tank would give you plenty of flow once you start growing corals. The nice thing about the MP40's is that their flow is adjustable and if you have two, one works as a master to the other.

Regards,

 

[roscoe]

You definatley need more flow. My tank is about the same size 270g and have about 20000GPH turn over in the DT. I run 3 MP40 vortecs and 3 tunze. No real noticeable dead spots. The fish love the flow esspecially the tangs.

 

[jill]

Thanks Richard and Roscoe.
I'm pretty new to this so I really appreciate the feedback.

I want to get more corals but don't want to until I get my nitrates to 0.

I would love to get vortecs but I don't think its possible because of the way the tank is designed. The powerheads have to sit inside the overflow chamber. What size tunze (or tunzes) would be appropriate.

Roscoe, you say you have 20000 gph turn over, is that including what comes up from the return pump? How does one calculate total gph? With my coralife returning 1740 gph and the #8 and # 4 koralia what would you estimate for my flow? Would I be better off with a different return pump?

My other question is about powerhead placement given that they all have to sit on the narrow back overflow wall.

Jill

 

[roscoe]

Thanks Richard and Roscoe.
I'm pretty new to this so I really appreciate the feedback.

I want to get more corals but don't want to until I get my nitrates to 0.

I would love to get vortecs but I don't think its possible because of the way the tank is designed. The powerheads have to sit inside the overflow chamber. What size tunze (or tunzes) would be appropriate.

Roscoe, you say you have 20000 gph turn over, is that including what comes up from the return pump? How does one calculate total gph? With my coralife returning 1740 gph and the #8 and # 4 koralia what would you estimate for my flow? Would I be better off with a different return pump?

My other question is about powerhead placement given that they all have to sit on the narrow back overflow wall.

Jill

No problem glad to help. OOOPS I mean 20000 GPH so equates to around 74x turn over and yes I have about 1200-1300GPH from the return splitting into two so it is not much flow from the return. All the flow is from the Tunze and vortecs. As for calculating flow just add up all your rated flow for each PH and divide by DT water volume and you have your hourly turn over rate. For the return pump, the one you are using wouldn't be my 1st 2nd or 3rd choice but it will do the job. Maybe upgrade to a 2 eheim 1262 or mag18 down the road or if you can do external pumps Sequence pumps are great. Why can't you place PH anywhere else besides the back wall? You don't have to wait until your nitrates to hit zero. It is sometimes impossible to hit zero on nitrates but there are plenty system that are. My nitrates are between 10-15 and I have been growing and coloring up SPS with no problems.

 

[trido]

I agree with Sarang (roscoe) on your return pump. I recently upgraded my return pump from a mag18 to an external and am much happier. I have near 18,000GPH of turn over in my 210 created form a CL and strategicly placed powerheads. If you do it right, you can put powerheads on the ends of your tank without too much visual interuption. I personally dont like the look of powerheads in the DT, but without spending a fortune on CL pump electricity. Powerheads is the price I pay.

Very nice looking display BTW. Since its a peninsula, I would recommend and over the top CL system to keep the uncluttered look you want. Take a look at the last few pages of my 210 thread in my sig line. You will see there is a powerhead on the front corner that isnt too obtrusive.

 

[roscoe]

Very nice looking display BTW. Since its a peninsula

Duhhh why didn't I see that LOL. I see why about the PH now. In that case if you do go with PH I wouldn't do the vortechs as you have the dry side showing. I would go with the newer Tunze they are pretty small in size and pack alot of power. However with that style tank I would do what Duane suggested. A over the top CL for the cleaner look.

 

[jill]

Thanks Sarang and Trido. Amazing tank Trido - just beautiful.

So, I am getting almost no flow from the Coralife 1740 return pump as it is split into 6 returns. I am going to take your advice and upgrade to a eheim as soon as I can but I got lost when you talked about "sequence external" pumps. Could you please tell me what that means or tell me where I could see one? Sorry to be so ignorant!


If I understand correctly I take the combined rated flow from the 2 Koralia's (3250 + 1200 = 4450) and divide by the tank volume.
So 4450/250 = 170. Did I do this right? Pretty low compared to your 18,000 Trido. So I will do the math with my new powerhead candidates.

My other concern is that they are in a bad place - one of you mentioned a "dead spot" and that's what I worry about too. I don't have a nice big overflow area (that weir is on the 24" wall) so I worry that the water hangs around in the tank too long... is that an unnecessary worry? Will the increase in overall flow from better powerheads cure that if it is indeed a problem?

I liked your idea of a ph on the outside 24" wall - I had considered running the cord over the top of the tank in the canopy. If I do this should I place the ph low - nearer the sand or closer to the top? I don't understand what a closed loop is. There is so much for me to learn about this hobby but luckily I really love it.

 

[trido]

Do a search for "Gyre" circulation. It may help you make some simple flow decisions.

Its late (bed time), otherwise I'd explain a closed loop to you.

Also, yes 4450/250= a 17.8X turnover. Not the end of the world but not fittong for todays standards for a reef tank. Just a mere four years ago, a 30x turnover was considered pretty high for a SPS reef. Now it seems were all shooting for a 50x and more turnover. Powerheads have come along way in the last few years.

 

[jill]

Do a search for "Gyre" circulation. It may help you make some simple flow decisions.

Its late (bed time), otherwise I'd explain a closed loop to you.

Also, yes 4450/250= a 17.8X turnover. Not the end of the world but not fittong for todays standards for a reef tank. Just a mere four years ago, a 30x turnover was considered pretty high for a SPS reef. Now it seems were all shooting for a 50x and more turnover. Powerheads have come along way in the last few years.

Thanks Trido. I'll look up Gyre and closed loop. You've helped alot. Nity nite!

 

[menace78]

Just a thought. I would change the 6 way return into maybe a 2 way over the top return from the sump and use the 6 return lines on the bottom for a closed loop return manifold and get a big external pump.
IMO that would be the least intrusive and surefire way to add alot of flow without the clutter of PH's.

 

[jill]

Just a thought. I would change the 6 way return into maybe a 2 way over the top return from the sump and use the 6 return lines on the bottom for a closed loop return manifold and get a big external pump.
IMO that would be the least intrusive and surefire way to add alot of flow without the clutter of PH's.

That sounds like a great idea! Someday...

 

[menace78]

That sounds like a great idea! Someday...

Wouldn't be that hard to do.
All you would need is the pump and some PVC pipe and fittings. sounds harder than it is and to help answer you'r question in another post. That is a closed loop
Too bad you'r up north of me, would make more sence if someone could explain it on you're tank instead of posts. Visual always makes more sence.
Eather way you go, GL with the additon of flow to you'r beautiful tank!

 

[CarlaW]

Jill, this is the set of articles that trido was referring to:

http://www.advancedaquarist.com/2006/6/aafeature2/view?searchterm=water flow

http://www.advancedaquarist.com/2006/8/aafeature/view?searchterm=water flow

http://www.advancedaquarist.com/2006/9/aafeature2/view?searchterm=water flow

http://www.advancedaquarist.com/2006/11/aafeature/view?searchterm=water flow

http://www.advancedaquarist.com/2007/1/aafeature/view?searchterm=water flow

Jake Adams was at the Tri-Cities conference this last summer, and he is a real interesting person to talk to about flow in a reef tank. Enjoy the articles, they ought to keep you busy for a while!!!!

 

[jill]

Jill, this is the set of articles that trido was referring to:

http://www.advancedaquarist.com/2006/6/aafeature2/view?searchterm=water flow

http://www.advancedaquarist.com/2006/8/aafeature/view?searchterm=water flow

http://www.advancedaquarist.com/2006/9/aafeature2/view?searchterm=water flow

http://www.advancedaquarist.com/2006/11/aafeature/view?searchterm=water flow

http://www.advancedaquarist.com/2007/1/aafeature/view?searchterm=water flow

Jake Adams was at the Tri-Cities conference this last summer, and he is a real interesting person to talk to about flow in a reef tank. Enjoy the articles, they ought to keep you busy for a while!!!!

Hey Charlie, Thanks for the articles. I have read and reread them they are very helpful. I guess one of the most important things I came away with is that turnover rate is not the holy grail relative to water flow. Part III states that hobbists should "move away from gauging the water movement in their aquarium by using "X" amount of turnover." In fact, Part V goes further saying, "the use of "turnover rate" to describe water movement continues to cripple the progress of more advance water movement techniques."
Its good to have a better understanding of the gyres. I guess I am going to have to experiment but having some background makes my decisions a little more informed. I got a Hydor Wavemaker last month with 4 powerheads and will continue to play with it.

 

[Whatever]

I was told when I got into this hobby many years ago, 10 to 30 times turn over rate. My current system I am designing is going to have about 80 times turn over rate.

One thing to remember is just because they say they have 3200 GPH flow does not mean that is what you get. By the time you add rock, corals, plumbing and other items that may block the flow you could end up with a lot less.

Another thing to think about is how was the powerhead rated to get that flow. Every company rates differently. Some rate at the output, some rate 3inch in front of the output and others rate in and output as flow. If they have 1600 GPH coming out they must have 1600 GPH coming in. Add these together and you have total flow.

On a closed loop the pump will be rated output only, if you do an over the top closed loop you might want to look at adding a Oceans Motions 4-way to get more of the random flow throughout your tank. Another option is to add sea swirls. You should be able to hide those pretty easy. You just put them on the rim of your tank about every 2 feet on one side.

They have other devices you can take a look at too. These are just some of the most common devices I have seen.

 

[CarlaW]

Hey Charlie, Thanks for the articles. I have read and reread them they are very helpful. I guess one of the most important things I came away with is that turnover rate is not the holy grail relative to water flow. Part III states that hobbists should "move away from gauging the water movement in their aquarium by using "X" amount of turnover." In fact, Part V goes further saying, "the use of "turnover rate" to describe water movement continues to cripple the progress of more advance water movement techniques."
Its good to have a better understanding of the gyres. I guess I am going to have to experiment but having some background makes my decisions a little more informed. I got a Hydor Wavemaker last month with 4 powerheads and will continue to play with it.

I guess what he may be trying to say in part 5, without him being here to help, is that maybe turnover rate isn't what it is cracked up to be???? The more important thing about flow, as far as I am concerned, is paying attention to your critters, and their needs, rather than being able to stick your chest out and brag about turnover. Hope I didn't upset anyone with that???
I am only turning my 300 over about 30 times, but yet I have healthy corals, and growth!!! I think one thing that isn't mentioned is the quality of skimming also, the more the merrier. This is all the part of a great big puzzle that we keep trying to fit the pieces into, an ongoing process so to speak. I think the more we get into flow "techniques", the more we are going to be able to be successful.
I really think he should try to update these articles, or at least make an attempt to, because methods have really changed in the past 2-3 years. JMHO