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? about flow....

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We have a 12G and a 3G tank. In the 3G especially I have been kind of resistant to high water flow and keep the powerhead turned down as stuff blows around and (being a noobie) seems to push the zoos and xenia around a good bit. I have had a few dead/low flow spots in the 3G tank and now have algae growing in those areas... Last night, I turned up the powerhead (as much as I didnt want to) to get water moving in those areas... after about 2 hours, everything seemed to be more healthy, the zoos and xenia were fully open, full and robust, the pseudochromis seemed to be enjoying the flow as well. The only one who wasnt enjoying it was a blue hermit that had hair algae growing on its shell so I pulled him out and cleaned him up and he went about his merry way foraging. The algae was like a sail and he was being "sailed" around a bit. Also all of the debris that kicked up cleared from the tank probably via the filters.


I have seen large reef tanks with surges set up and its pretty powerful as far as moving the corals/polyps/zoos around but I guess they deal with 20' waves crashing on them so clearly they can handle it even though it looks like it could be stressful.


I guess my question is how much flow is too much or too little?????


In the 3G picotrope is the stock HOB (supposedly 40GPH but once its got some loading in the filter its prolly more like 25-30) and a 40 GPH elite hagen powerhead that I usually keep on the lowest setting, maybe lowest+1 notch on the flow adjust. When I turned it up I set it to about half. I know the recommendation is 5-10 times tank volume for flow so in the old configuration I was looking at around 25GPH with the HOB and maybe another 5 GPH from the powerhead for a total of 30GPH Now I am probably closer to 45 GPH (25GPH withthe HOB and maybe 20GPH on the powerhead) which is more like 15X the tank volume... I have also seen some threads saying the flow should be 10-20 times the tank volume and the new confiuguration puts me in that range.


The other thing I would like some input on is since its a small tank, I dont have a lot of placement options nor can I put in 2 powerheads with a wave timer to mix up the flow... are there any issues with running the flow in the same direction all the time? I guess every few days I could move the powerhead to the other side if necessary...


Any thoughts comments, suggestions is appreciated





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well in a small tank it's nearly impossible to get the flow to hit in all directions and area's without having the water circulate in only one direction, i see no issues with water comming in only one direction as long as the coral looks good, but for SPS i think it would be too stressful, random flow is needed much more for SPS than Softies


In my 5.5 gallon, for flow


I use


2 aquaclear 50's HOB's, both at full bore, this made the sand in the front of my tank move towards the back as well as waste, and it also gave me some dead spots to the back that i didn't like,


So to fix that i also added a korlia nano PH to the display and barely anything ever lands on my sandbed now, and the corals seem to continue to enjoy it more and more when i give them this much flow (granted i wish i could turn the koralia down a notch or two, because my flow is insane, but i found a spot for it and when my colonies grow out then the flow will be perfect)


i run my 5.5 gallon with


2 aquaclear 50 HOB's at full bore


1 koralia nano


The 2 AC's keep the flow infront of my rockwork, while the Koralia nano oscelates the flow back and forth (infront and behind the rockwork, keeping everything suspended so my HOB's can take it out)


this setup gave my tank insane flow but it aslo makes the flow completely random and slosh like


My understanding is this,


The torch coral in my tank hated the flow as i think almost all softies would, but the SPS, Zoa's and Shroom's seemed to thrive better with the more flow i threw at them, i didn't really want to put any powerheads in my tank (because of limited space) but the koralia nano is single handedly the best powerhead i have ever seen, and because it's not a direct stream like other powerheads it makes it easier to get the slosh effect, i only wish they had a knob or switch so you could adjust the flow (it's a lot for a 5.5)


at this point now i'm well over 100x turnover for my tank volume


2 AC 50's at 200gph on a good day when clean, lol

1 koralia nano rated for 240 gph on a good day, lol


so i have 640 gph on my 5.5 tank, lmao

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With too little flow the top of my sand looked like crap, watse,debris and detrius very noticeable and everywhere


With the high flow i have in my tank the sand is ontop of the waste,debris and detrius, so i never notice it and it give the tank and over all cleaner look, though i do syphon the sand i can get to 2 times a month

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I have a 2.5 with a barebottom so I have more flexibility with my flow...no sand blowing everywhere. At this point the tank is just LR, nothing else. I have a minijet 404 pushing water from a side refugium built inside the tank. The water flow is along the bottom back corner crossing the tank from right to left. That little pump is wide open and rated at, I think, around 120 gph. Additionally, I have a nano HOB filter that probably moves 50ish gph.


The flows work well together, the cross flow hits the opposite side of the tank and is deflected in all sorts of ways. The HOB filter alters the flow even more.




That is not enough flow in my tank. I'm looking at replacing the minijet with like a Fluval 305 canister filter with nothing in it. This will run about 200 gph and add about a gallon of water to the system. Hopefully 250 gph will be enough flow in my 2.5 gallon tank.

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corals need flow. in my 55g i had 2x1100gph seios a mad 5 return and a mag 9.5 cl. just for a 55g

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