Hi guys, with my new tank I want to run 2x closed loop systems. My tank is 250 liters. The two pumps are 1400lph each. And the return is 4000lph. Will I need more flow to get rid of dead spots?
Closed loop
- Thread starter Jaun_marine
- Start date
Where do you want to supply the closed loop system from, I am doing a makeover on a 1200 x 600 x 500 tank at the moment, and I ran into problems with the flow I wanted to get for the closed loop system and the return. Originally I wanted to use the coast to coast skinny overflow with two outlets one to feed both the sump and the other the closed loop system. I am running external pumps, but the head on the overflow for the volume I wanted was too high, so I have had to change my design a bit and reduce the flow on both the return and the closed loop system which was too high anyway.
By the size of your flow pumps, presumably you want to put the pumps in the sump, (which is why I asked my original question) if that is the case, my suggestion would be to use two controllable DC pumps for the closed loop, and put the closed loop nozzles in the front corners of the tank where they can pump onto the display area of the tank, with the returns up the back corners. (four nozzles in total).
The more experienced reefers may confirm that you have to be careful how you feed the closed loop system, especially if you are feeding into the sump.
By the size of your flow pumps, presumably you want to put the pumps in the sump, (which is why I asked my original question) if that is the case, my suggestion would be to use two controllable DC pumps for the closed loop, and put the closed loop nozzles in the front corners of the tank where they can pump onto the display area of the tank, with the returns up the back corners. (four nozzles in total).
The more experienced reefers may confirm that you have to be careful how you feed the closed loop system, especially if you are feeding into the sump.
leslie hempel
Professional Aquarist
loved closed loop back in the day but with today's technology of pump it's easier and cheaper to stick to pumps.
as the scape chages it can have a impact on how you designed your flow to effect your reef.. pump are quickly able to be repositioned and adjusted to suit.
also leaks do occur an it can be nightmare to fiddle with
as the scape chages it can have a impact on how you designed your flow to effect your reef.. pump are quickly able to be repositioned and adjusted to suit.
also leaks do occur an it can be nightmare to fiddle with
I wanted to run all my closed loop pumps from the side. The right side. Each pump split into two pipes with lock line.
The blue is the overflow.
The green is the lockline.
The green is the lockline.
NO WAY
on a 250L tank, 2 cheap Sun Sun 3000L/h pumps could not even be enough for a softy tank. After all bulkheads and elbows, you will be lucky to get 1000L/h out of each outlet.
Plus its better to exclude the return pump in the tank turnover rate.
What size pump do you suggest?
Depending on closed loop setup, expect 15% or even more lost due to back pressure. If you want equivalent to a 4000L/h powerhead, you should look at about 5000L/h return pumps.
Other issue is that return pumps are a lot heavier on power consumption than normal powerheads. Even DC pumps, will use double or triple the wattage to deliver the same flow rate than a powerhead.
Alternative is to mount pumps like Tunze or Seio with a narrow round front end, to drill holes big enough in that back panel so that the pump sits behind it, with the round front end sitting tightly into the hole. So the pump sucks water from behind and blow it forward into the display. Flow into the back chamber can be by slits on the sides. Will not use an overflow design to fill this back chamber as that could lead to an empty chamber.
Best is to just place the pumps so that it is not in the view.
Other issue is that return pumps are a lot heavier on power consumption than normal powerheads. Even DC pumps, will use double or triple the wattage to deliver the same flow rate than a powerhead.
Alternative is to mount pumps like Tunze or Seio with a narrow round front end, to drill holes big enough in that back panel so that the pump sits behind it, with the round front end sitting tightly into the hole. So the pump sucks water from behind and blow it forward into the display. Flow into the back chamber can be by slits on the sides. Will not use an overflow design to fill this back chamber as that could lead to an empty chamber.
Best is to just place the pumps so that it is not in the view.
Another issue about closed loops is that you in effect build a drain into your tank, so if plumbing starts leaking, or the seals on the pump fails, there is a chance your whole tank will drain completely. If overflow or return plumbing leaks only your sump will run dry.
Can you not build a wavebox into the one corner to hide pumps?
Can you not build a wavebox into the one corner to hide pumps?
Totally understand this as I also didn't want any pumps in my display when I was looking into the Closed loop. I am not going to try and change your mind just give you the reasons I went for the RW4.
I didn't want any pumps in the tank like you, but then I realized with all the lock lines and ends it actually takes up more tank real-estate then you think. What I ended up doing with the RW-4s, was place them on the back on the tank facing forward, both in random mode.
In terms of maintenance its a lot easier than a closed loop. As there you have to add valves, make sure the seal are perfect etc, where with the pump it takes me a min to remove it to clean it.
Just my pros and cons.
I must admit, I agree with Juan in terms of not wanting pumps in the display area. Firstly they look ugly, and there have been a lot of situations where nennies have been sucked into the flow pumps and have contaminated the system.
I agree with RiaanP's comments regarding pump sizing and loss of efficiency, and I think his suggestion of placing the pumps in the tank is a good idea, however the only point I don't completely agree with is having the flow at the back of the tank. To me the whole reason of having a closed loop system is to replace flow pumps, and be able to provide flow onto your corals etc. which are normally viewed from the front of the tank, and therefore the closed loop flow should be from the front of the tank towards the corals etc.
The advantage of what he suggests is that everything is self contained in the tank and the system operates as a true closed loop system, although it does use more real estate in the tank.
I hear what Hotdog83 says, but the drain you build into your tank for the closed loop should not allow the entire system to be drained, and should only allow enough water to keep the designed flow rate. The plumbing leaking could apply to any system, closed loop or return, but that is part of life.
With regard to your sketch, I would only have two closed loop returns. In terms of the comments made so far, I would suggest the use of RiaanP's pump proposal, but that you arrange the plumbing so that the closed loop returns pump from the front corners of the tank onto the display area, and the returns from the sump pump from the back corners of the tank, that way you have four nozzles feeding the tank.
You obviously have to work out what would suit you best.
I agree with RiaanP's comments regarding pump sizing and loss of efficiency, and I think his suggestion of placing the pumps in the tank is a good idea, however the only point I don't completely agree with is having the flow at the back of the tank. To me the whole reason of having a closed loop system is to replace flow pumps, and be able to provide flow onto your corals etc. which are normally viewed from the front of the tank, and therefore the closed loop flow should be from the front of the tank towards the corals etc.
The advantage of what he suggests is that everything is self contained in the tank and the system operates as a true closed loop system, although it does use more real estate in the tank.
I hear what Hotdog83 says, but the drain you build into your tank for the closed loop should not allow the entire system to be drained, and should only allow enough water to keep the designed flow rate. The plumbing leaking could apply to any system, closed loop or return, but that is part of life.
With regard to your sketch, I would only have two closed loop returns. In terms of the comments made so far, I would suggest the use of RiaanP's pump proposal, but that you arrange the plumbing so that the closed loop returns pump from the front corners of the tank onto the display area, and the returns from the sump pump from the back corners of the tank, that way you have four nozzles feeding the tank.
You obviously have to work out what would suit you best.
Thanks for all the suggestions and help guys. I will buy two wavemakers to add to the flow and then run one closed loop system from the section on the right hand side of the tank. The return lines will be from the other sides of the tanks so I should get a nice flow pattern with two wavemakers on pulse and the closed loop systems on a timer and then the return on max strength.
This will give me 11000lph flow through my 250liter tank
What I mean is any hole at the bottom of the tank will drain a tank irrespective of size of hole if a seal fails on closed loop pump.
And if overflow or return leaks your whole tank won't drain, as overflow and return pipes don't normally flow from bottom of tank.
I had to search for these pics.
OK, it was a 1.5m tank, by .75 by .75m Running 2 Reeflow Super Dart pumps of 13000L/h each
6 outlets, from the top 2 at each side, and from below, on a side.
the pumps
I ended up closing the bottom 2 outlets just so that the top 4 can have descend flow. In theory I should have had over 6000L/h per outlet when running 4, but in reality it was less than 3000L/h.
That pic might look like a lot of flow, but when full of water the flow was not that great.
OK, it was a 1.5m tank, by .75 by .75m Running 2 Reeflow Super Dart pumps of 13000L/h each
6 outlets, from the top 2 at each side, and from below, on a side.
the pumps
I ended up closing the bottom 2 outlets just so that the top 4 can have descend flow. In theory I should have had over 6000L/h per outlet when running 4, but in reality it was less than 3000L/h.
That pic might look like a lot of flow, but when full of water the flow was not that great.
That I agree with which is why the outlets for the overflow must be positioned high enough to allow for the flow rate, but not so as to drain the tank, that way you won't lose all the water in the tank.
RiaanP's photos show that where his outlets are positioned, if there is a failure you won't drain the tank.
RiaanP, did you have problems with the plumbing itself, or just the flow rate? The reason for the question, is Idol have used external pumps and plumbing for years, presumably without problems, otherwise they would have gone away from using them.