Advice on circulation in my new tank.

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Laiken

Feeder Fish
MFK Member
Sep 20, 2018
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I am trying to learn a little about water circulation. I have a 125gal tank with a fx4 canister. When looking at the tank from the front the inlet is in the left rear corner about 4in up from the sand. The outlet is in the right rear corner about 3in below water level. The outlet has a duel "water jet" type head on it. One of the jets is pointed slightly up and back towards the inlet. The other is pointed slightly down and towards the front wall of the tank. Hopefully ive explained that well enough to get a mental picture. There is also a 18in airstone centered along the rear wall. Im thinking i have plenty of surface agitation, however im unsure about the overall flow of the water. There is obviously a "dead" spot directly below the outlet. There also seems to be very little flow along the bottom of the tank. Should i be considering a circulator of some type? Thanks for any input.
 
Hello; I have done the sort of thing you are thinking of. Bubblers in the corners will create some circulation but it will be sluggish.
I once modified a HOB so that the water being pumped back into the tank was diverted to the left and thus away from the pickup which was directly below. It sort of worked but I still had dead spots where detritus would settle. A few years later I broke the tank down and used glass pieces of various widths and lengths to create a tiered ( three distinct layers) at three depths. I filled the these with gravel and wound up with levels staggered from the highest at the far left and in the back down to a lowest level right near the pickup. It worked very well with only a single HOB but was only a 20 gallon long. I guess I am saying it can be done with some effort.
 
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Im thinking i could do something simple like put a circulation pump/wave maker on the lower right side below the canister outlet. Hopefully it would create a current that flows along the bottom of the tank that keeps mess off the bottom and pushes it toward the canister inlet. Im just not sure my thinking will work out. Also not sure what size would be right if my thinking is correct.
 
Im thinking i could do something simple like put a circulation pump/wave maker on the lower right side below the canister outlet. Hopefully it would create a current that flows along the bottom of the tank that keeps mess off the bottom and pushes it toward the canister inlet. Im just not sure my thinking will work out. Also not sure what size would be right if my thinking is correct.
Hello; Give it a try. I tried to just boost water movement myself at first. Went to the other stuff later on and over several years of arranging levels in tanks did find something that worked. Not sure the in the water circulation pumps were around back then. Any more I just get the stuff out with a siphon when I do a WC.
 
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Im sure ill be doing weekly water changes so really the gravel vac will prob work. The circulators seem to be fairly low cost so i may just give it a try. Ill wait and see if someone chimes in with some first hand experience. Thanks
 
My returns on both my 180's are very close to the surface so that takes care of surface agitation. However it didn't do a great deal for bottom circulation and so i had debris building up on the bottom which is always unsightly. Then I installed a powerhead in each. Each one was midway down the glass at one end pointing slightly down. I've never looked back since, I don't even vacuum my substrate anymore (I only have a very thin layer of substrate anyway).

It helps a lot that my outlet is not surface skimming, my debris gets sucked from the bottom of the tank on both my set ups. So debris just slowly gets blown along the bottom of my tanks to the end where it gets sucked up. If you have surface skimming you may still have heavier debris sitting on your substrate.
 
Sounds very simular to what i was thinking. What type of powerhead are you using? Thanks for the advice.
 
the first one I got was a jebaoRW120. this is a multi speed beast with 20000 litres per hour on the highest setting, absolute overkill for my 180. I have it on its lowest setting on timer so it's only on during the day and even on the lowest setting it is very powerful. so when I got my second one I decided to go smaller and I went for the jebaoRW40 which is also multi speed but this one I can run at full power and it's just right. the RW120 was over £100, the RW40 was about £40. you can get other models for a lot cheaper.
 
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I've never looked back since, I don't even vacuum my substrate anymore (I only have a very thin layer of substrate anyway).
Hello; Have you done a vac of the substrate anyway since this setup has been running? Just curious as any setups I have managed have so far left stuff in the gravel.
 
Hello; Have you done a vac of the substrate anyway since this setup has been running? Just curious as any setups I have managed have so far left stuff in the gravel.

like I said I only have a very thin layer of gravel, and I mean thin, as in you can see the bottom glass through it. this factor coupled with the good flow means I don't get any debris building up anywhere. it's quite funny sometimes, my RTGG will do a big crap and it just bobbles along the bottom until it gets to the end of the tank where my outlet is, and up it goes, sucked down into the sump. but also, it really really helps that my outlet is at the bottom of my tank at substrate level. if I was surface skimming only I think i'd still have to vacuum the bottom once in a while.
 
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