Flow in a BB system?

[Maxx]

I saw a thread on TRT where Middleton Mark stated that flow in a BB tank is often misdirected. He said initially his flow was directed along the bottom and corners of his tank and his tank wasnt doing as good. He still had lots of hair algae. Once he changed the flow and directed it to the rockwork in his tank, his hair algae cleared up. Bomber/Jerel agreed and said that was the trick to BB tanks.

http://www.thereeftank.com/forums/showthread.php?p=371532#post371532

So my question is:

What is considered optimal flow for a BB tank? How should it be directed? To the rocks, or all over the place? If you direct the flow to the rockwork, how do you do it a way that it doesnt harm the corals?

I'm considering purchasing some eductors for lil 58 in order to increase the flow to the point that no detritus can settle out of the water column. My Iwaki 55RLT is great, but I've been wondering if I'd be better off having used an Iwaki 70.
I'm curious here......gimme your feedback Mike!!
Nick

 

[spooda420]

Nick,

I have 2 - 6080 Tunzes in my tank (120g) aimed toward the bottom back of the tank, This allows my to have the detrius to settle out in one main spot where it its easily sucked out.

the total tank turn over is about 45x (37.5x just with the tunzes) how much more would you think is even necessary?

I was actually thinking about putting aonther 6080 in there aimed across the bottom front.

however with the set up i have now I am pleased with the flow Im just afraid if I add one more tunze that the fish would not have a low flow area to chill out in... ya know what i mean vern?

 

[Maxx]

Chris,
I know exactly what you are saying and that is a concern of mine. I'd rather avoid the whole whitewater toilet flushing llok in my tank, but I'm a little concerned I may not have enough flow, or that it may be misdirected. Believe me, I really rather not have to buy aything else for this tank except livestock right now. but I am noticing a fair amount of detritus settling directly infront of the overflow. This will change when I set up the chiller, as I will be using an Iwaki 40 RLT to run that directly back into the tank. I will use two returns and will use two more Loc-Line Y's to split those returns into a total of 4 that will be directed down towards the areas where detritus is collecting.

I guess my real cocern is where should I have my flow directed towards? The rock or all over? And if I direct to the rock, is there a way to do this that wont harm corals? Or am I just making this WAAAAYYYY harder than it has to be?

Nick

 

[szidls]

Hey Nick,
I don't see the corralation between where you point water movement sources and hair alge in a BB tank. As you said you want to keep waste in suspension until in can be removed manually as in the sump. You must keep it off the bottom of the tank by either siphoning it or using a water movement source to keep it suspended. You also need to blow off your rock and corals periodically to keep detritus from setteling and causing an alge outbreak. Either way all the detritus has to be removed.
Scott

 

[szidls]

Nick,

As to flow in the tank. If you are keeping sps they definately like higher flow and can stand more direct water. I think you are looking to create random flow so the water movement isn't always the same and comming from the exact same direction. Say opposing power heads on a wave timer. Or closed loop with an MBV?
Scott

 

[Maxx]

Scott,
I have an Iwaki 55 RLT running through an OM 4 way unit, so I have the random flow...I was just wondering if it was deemed better to have the flow random across the tank, or random across the rock?
Nick

 

[szidls]

I guess I would want randdom flow in the whole tank.........No dead spots. This would include rock and corals and BB. The OM looks like a cool devise. I guess it's just a matter of aquascaping and trial and error with your plumbing placement. Try and make it easy to siphon any dead spots.

Scott

 

[mojoreef]

The problem Mark had is not really related to the bottom flow. What we are trying to do is to keep detritus and waste in the water column. Waste/detritus is going to come from the fish and from LR, the concept is to keep it from settling either on the rocks or the bottom. If you just direct flow to the rocks you will end up with detritus on the bottom if it is not also covered. The same applies visa verca. Mark probibly didnt have good flow to keep his rocks clean and thus the shedding detritus became food for algae as it sat thier. Now you dont have to have every square inch of either the rock or bottom covered with good flow. If thier are areas where the flow doesnt do the job you just have to do it manually. For me I have about 4 spots in my tank on the bottom where the detritus builds up, Once every few weeks a do a 5 minute syphon and it gone. On the rocks I just take a small PH at the same time and give the rocks a quick blow. The whole operation is about a 1 hour total job, with cleaning.

Again the concept is to keep detritus and waste in the water column and out of the tank to a skimmer or simular peice of equipment. I dought if ayone has the perfect setup where they can get every little spot all the time. For those areas that are left just do a quick maintence regime once every few weeks or so and its all good. Dont keep adding flow just to try to get to the perfect scenerio it wont work, lol trust me.


Hope it helps


Mike

 

[middletonmark]

Bingo Mike ... but I also found in the `rock shedding phase' that there was such a huge amount of detritus that even bi-weekly turkeybaster episodes still had it piling up too fast. That just in terms of quantity - too much was being produced leaving small pockets that quickly fed macro-algae.

I personally think I focused a little too much on keeping the bottom clean and keeping things in suspension ... without focusing on getting that suspended material up+over the overflow [flow change to make sure larger particulate made it, which it wasn't at first] ... as well as to remove the `settling spots' on the live rock.

Any discussions about flow are hard to describe without us standing in front of a demo-tank ... but I guess I meant my comments far more as a `don't be suprised if you need to change things a little too, keep an eye out!' than a whole new method of flow. Until I got the larger particulate going up + over the overflow to the skimmer/etc ... my export wasn't working that well [beyond the siphon hose].

I guess I'd just suggest doing what you can to allow customization at a later point ... and not being shocked if you have to play with it some. I know the BB experience for me has taught quite a few lessons in design, equipment, and husbandry that I didn't know before ... I'd just keep an eye on what happens with your particulate/rockwork.
Turkeybasting is always a good idea, and a good way to see whether maybe some flow alterations might be good. If you can baste every day + get a pile from an area ... watch it. If you can baste bi-weekly and get the same amount - better. Just make sure you don't have excessive settling was my real point.

But as usual, here + elsewhere, my morning pre-coffee rambling makes a long, confusing post.

You know, you could all just come over to my house and check it out

 

[mojoreef]

Hey Mark. What do you mean by rock shedding phase. Were you in a cycle or was the rock old?? What I have found is that the detritus for the most part is very lite and will suspend easy, that being said it can also be a pain in the butt to get up off the rocks and bottom. This is where randomising your flow really come into play.
A good example is Alberto and his new tank. He hadnt hooked up his valves yet but still have very good flow and open rick work, when he got the valves going and hey switched over his tank turned into a detritus storm. Detritus will always find a plce to build up, we do our best with designed random flow the balance is manual.
Once you get something like hair algae the game changes a bit. The algae will actually capture detritus and hold it in its mass for feeding later, so you really need to blow in side it to keep it clean. I usually only clean my rock work once a month, man if that really. But I just get a small power head and blow it into the water column, it only take a few minutes and works pretty well, at the same time I put a sock on the drain line to capture what I can.

hope your past the problem

Mike

 

[middletonmark]

I meant that I had a SSB [1/2"ish]... and removed it. For the next 3 or 4 months, there was a remarkable amount of detritus/substrate that would emerge. Almost daily ... I could siphon it out almost daily for a period and it would appear the next morning. I pulled the rocks to remove the substrate, but just too much `in the rock' which emerged over time IMO as bacteria/etc loosened it up/out.

IMO, the rock was dropping the substrate/built-up-detritus ... as much of it was the 1-3 mm stuff that was in previously. Which didn't want to suspend itself, and attracted more buildup if left around.

As Maxx has a 58 like me ... 36 x 18 x 21 tall - I've found getting the crud `up and over' is probably a little tricker than a longer tank and definitely harder than my shorter tank of same type. Maybe that's me, though ... I realize my tank/husbandry are maybe a little more idiosyncratic than most But perhaps this fact also caused my needing to change flow ... as there's more vertical space than front-back in the tank.

I felt like it took a few months to really clear the last bits out from my very porous MI/etc rock. It was near the end of this when I changed the flow patterns during the macro-algae boom [no green hair, some unusual types] ... could have been the salt, could have been a number of things [RO/DI needed filter changing ...]

But ... I trusted the system and just altered where stuff settled with more on the bottom and few if any settling spots on the rockwork. A month later - obvious results as the larger macros bleach and die. In the last month ... even the red hair small patch I got on a frag a year ago + refused to die ... gone. No 'fuge, no chemical media ... all algae gone.

It took a little trust, a little flow tweaking, and some learning ... but after that `ugly phase' it became obvious the BB system was working for me as I watched the algae disappear and corals improve further.

By my experience, playing with the flow sure helped. But it's so aquascape, tank, situation dependent ... if you're having issues - IMO it's something to consider as it doesn't require buying anything. If not, leave well enough alone as I'm trying to do as my tank is IMO at it's best ever, nice and stable, pest-free.

 

[mojoreef]

Good post Marc. I didnt reaalize you had sand. What ends up happening when rock sits on sand is that it kinds of works backwards from normal. Instead of the rock shedding via the bottom with gravity it tends to suck up detritus and nutrients from the sand and spew them out the top.
Once your rock now has reach an equalibrium and you keep up with decent husbandry it shouldnt be a problem. Hope all stays well


Mike

 

[Maxx]

Wow...I'm gone for a couple of days and sorts of intelligent well informed people show up and explain things. BTW, its good to see you here too Mark. I cant go to a reef board w/o bumping into you. I'm not complaining, you seem to be in the middle of alot of interesting and thought provoking discussions.

Anyway....I've definately tried to design as much flexibility into my tank as possible. This rock was cooking in a 55 gallon tank downstairs in my basement for the better part of 6-8 months. I've basted and used a powerhead to blow crap everywhere and it looks like its getting to be less and less each time. I was just trying to find out of there was a preferred way of setting this up.

I've ordered two penductors from KTH and will hook them up on two of my returns to see how they perform. If they work well, I might order more. If they work too well, I wont. I really dont want the Tsunami effect in my little tank.

Mark, is there anyway I could get you to post up a full tank shot of your 58 and describe your flow pattern? This would help me figure out how you have yours and give me something to model mine after. Mike has such a large tank it would be comparing apples to oranges....I know the principles are the same, but I think his tanks size allows him to utilize things I cant on mine.

Nick

 

[middletonmark]

Nick ... I'll try to get one up tonight after work. Not a bad idea, but probably need another photo or 3 to demonstrate.

 

[Maxx]

Cool. Thanks Mark.
Nick

 

[middletonmark]

Ugh, I'm working on it, but not done. Pesky work has me training someone in, so I actually have to do work related stuff most of the time

 

[middletonmark]

Well, I got some things together. But do realize ... work in progress. Actually probably going to add a 6000 stream in place of my `hidden seio' ... and remove the MJ's, replace left side one with the spare Seio. Maybe remove either eductor or visible Seio to cut down on visible presence [moreso in pics than reality IMO].

Anyway ... attached are a few pics. I've always been a little overkill on flow for the last year ... had a 1000 + gph closed loop/spraybar for a while ... almost `toned down' now as I realize that #'s aren't everything they seemed to be.

Return is a LG 3-pressure series, supposedly around 550 gph, reduced I'm sure maybe 1/3 by the eductor? ... yet generating a heck of a lot of flow in the upper water column and beyond. Despite the GSP's growing on the eductor ... considering removing it for a while again, see what I like better.

Seio 820 on right upper side ... on 6 hour on/off timer ... runs in opposition to the eductor and creates nice swirling water. El cheapo `tidal mode' sorta, in a way.

Seio 820, under removable piece of LR, hidden as in pic. Aims downward and behind the back of the rockwork ... which I've left fairly open [this area is a big open piece of tonga ... strong, yet open for flow]. Does a good job keeping the PITA to siphon areas free of debris ... which collects right in front of the bubble, and about 4" to the right of that - easy to remove spots. This Seio I will likely replace with a Tunze [preparing for the next upgrade ... probably running it 60% power until then].

MJ 1200, right rockwork area, under lower frag rack which isn't apparent in front-on shots ... serviceable [frag rack] ... blows down + forward. On wavemaker ... seems to get the areas in/around my left rockwork including the shelfy piece that things sit on.

MJ 1200 on left end, back ... facing somewhat down and to corner. This area IMO is the 58's problem spot ... just hard to get flow to - and important to in order to keep things suspended over the overflow. Hate having the ph there .... yet when it fires you can see the stuff stay in suspension near the overflow. Probably will replace this with one of the Seios, when I remove the MJ's.

Anyway, a few pics ... feel free to ask questions. Or tell me to get my own thread

--- Pics ... 2 of full tank, with eductors/etc visible. One of lower right rockwork ... very open + with MJ marked shooting kinda through this area. One of left side by overflow [old style 58] ... the problem area MJ.

 

[middletonmark]

And pardon the large image, but this one probably serves things best:

 

[Maxx]

Thanks Mark. That does explain a fair amount to me. I've been noticing some nuisance hair algae beginning to crop up along my cuttingboard and on my rock work. I have a Maxi jet 900 I use to blow the rocks clean of detritus often as possible. And I usually use a filter sock to catch the stuff from the overflow. It only stays on for 3 days, then is removed. I'm just trying to get a hang of how you guys have your flow set up prior to putting fish in my tank. I've just glued up my chillers return plumbing and will have that hooked up by morning hopefully. I just made these up to kinda show what I'm going for here.

Here is a full tank shot. The blue indicates flow patterns from the closed loop, (Iwaki 55 RLT running through an OM 4 way.) Yellow is where I will direct the flow from the sump via chiller in order to hit the areas where detritus collects, which is convienantly shown as Brown circles. The Brown circles with the yellow are the two I'm primarily trying to hit since they are more annoying to reach by siphon.

Here is a top down shot showing the same idea. Colors are slightly different though. In this one, Blue represents flow from top closed loop returns, red indicates bottom closed loop returns and yellow circles indicate both where I want the sump chiller returns to hit for detritus removal. Basically just push to where I can easily get it with the siphon.

Oh yeah, almost forgot. I will using an Iwaki 40 RLT to run the sump return. I had it lying around and the chiller constricts down to 5/8 inch plumbing so I'll need a pressure pump to get the most out of it.

Any comments or suggestions are welcome and appreciated.

Nick

 

[middletonmark]

How I love those with the center overflow ... why didn't they make them like that before?

Anyway ... griping aside, that's a nice flow setup. Given corals need to be put in - flow is going to have to be tweaked for them first IMO. Whatever happens to the detritus, if the corals aren't happy with the flow - change needed.

It looks like a really sweet, really well done flow setup. The more leftward/back detritus area seems sorta like a pain ... [esp once corals on rocks] and is the worrisome one IMO.

The one thing that you might want to experiment with [I know, adding a cord ] ... would be some sort of flow blowing things `up and over' towards the front of the overflow - to make sure the suspended debris doesn't just goes in circles but is given to the skimmer. IMO, that's about the only thing I can see that would need to be considered or played with beyond just changing how outlets point.

But when you blast off your rocks ... watch how it goes over, and if larger/smaller pieces don't seem to make it to the overflow.

I've filter-socked, but now generally throw them on overnight once or twice a week ... before I take them off I siphon the bottom of the tank through them [in the sump, just siphon into it] so that I get all that in the sock, then remove and wash. No idea if multiple days cause a problem here ... just thinking out loud, not `knowing' out loud.

I'll be thinking Maxx ... just wish we could visit each other's tanks and learn so much more that way. Though we'd probably end up talking about corals and drinking too much beer :lol: