closed loop question...

[coralcruze]

I'm going to be drilling through the bottom of my fish tank for (4) 3/4" supply and (1) 3/4" return. tank is about 100 gallons. I plan to get a pump that is rated about 2000 gph. question that I have is... if I have 4 supplies one to each corner, how should that be plummed in order to get even flow through each? the tank is a square 36" x 36" footprint so I was thinking to run lines from each bulkhead to a manifold and then to the pipe. the manifold will be a section of pipe with a three tees and one 90 deg elbow which the pipes will be connected to. will there be even flow or am I going to need to adjust the ball valves near each supply in order to get even flow? is there a trick to this so I can minimize the fine tuning req'd? any plumbers out there welcome. thanks

 

[Reefmonster]

The only trick is to fine tune the ball valves. Also...Don't forget a Wye Check valve on the return because if the pump fails you'll be looking at a flood, and an empty tank.

I'd use overflows, and standpipes instead of drilling the tank. A disaster really if you do it wrong, or don't do a good job with a bulkhead. A failure would mean a flood and an empty tank....just my $0.02. YMMV

PVC is cheap, and can be configured any way you like, but it is up to you if you want to drill it, just remember that water weighs 8.5LBS per gallon...Rubber o-rings do eventually wear out, so be carefull where you put your holes.

:worried2:

 

[ruprecht]

I have no idea why the poster above is referring to a possible flood. It's a closed loop thus impossible.

As long as the depth of each supply is equal there will be little need to balance the inflow of water. The only way you could tune it would to be to install pressure gauges and ball valves but I believe that to be unnecessary. There are 5-way fittings that would work well for your needs. Your flow rate of 2000 gph is about the maximum for 3/4", so makes sure your cemented slip fittings are sound.

 

[Reefmonster]

I have no idea why the poster above is referring to a possible flood. It's a closed loop thus impossible.

As long as the depth of each supply is equal there will be little need to balance the inflow of water. The only way you could tune it would to be to install pressure gauges and ball valves but I believe that to be unnecessary. There are 5-way fittings that would work well for your needs. Your flow rate of 2000 gph is about the maximum for 3/4", so makes sure your cemented slip fittings are sound.

Ruprecht...Don't flame. Besides leaks are not impossible, only improbable. Saltwater has a way of degrading things, and sometimes bulkhead leak. Closed loop is not the correct term here because of the simple fact that there are bulkheads, and once in a great while they fail. A true closed loop system would NOT rely on drilling a tank, but rather using Schedule 40 or schedule 80 conduit to create a completely leak-proof closed loop system. The fact that you say "makes sure your cemented slip fittings are sound" implies that there is a possibility that they could fail. Like I said in my post to the OP...Be very careful or you will end up with a flooded room and an empty tank.

BTW...I've been a plumber for 14 years, even though I have a degree in Marine Biology...lol :hmm3:

 

[coralcruze]

I have no idea why the poster above is referring to a possible flood. It's a closed loop thus impossible.

As long as the depth of each supply is equal there will be little need to balance the inflow of water. The only way you could tune it would to be to install pressure gauges and ball valves but I believe that to be unnecessary. There are 5-way fittings that would work well for your needs. Your flow rate of 2000 gph is about the maximum for 3/4", so makes sure your cemented slip fittings are sound.

awsome advice... thanks I will pay special attention to the slip joints and glueing. any tips? I was also confused a bit as when a pump fails in a closed loop water remains in the loop not on the floor. sure I guess bulkhead fittings can fail so I'll be sure to spend the extra money on schedule 80 bulkhead instead of 40 and maybe use some silicone on the inside of the tank after the bulkheads are installed may not hurt. thanks.

 

[coralcruze]

Ruprecht...Don't flame. Besides leaks are not impossible, only improbable. Saltwater has a way of degrading things, and sometimes bulkhead leak. Closed loop is not the correct term here because of the simple fact that there are bulkheads, and once in a great while they fail. A true closed loop system would NOT rely on drilling a tank, but rather using Schedule 40 or schedule 80 conduit to create a completely leak-proof closed loop system. The fact that you say "makes sure your cemented slip fittings are sound" implies that there is a possibility that they could fail. Like I said in my post to the OP...Be very careful or you will end up with a flooded room and an empty tank.

BTW...I've been a plumber for 14 years, even though I have a degree in Marine Biology...lol :hmm3:

I dont think hes flaming you... You stated that if the "pump"fails than you will empty your tank on the floor. but you make a valid point about bulkheads. I wish I could use a standpipe instead but it will kill the look of the tank. Hence the closed loop system.

 

[ruprecht]

Ruprecht...Don't flame. Besides leaks are not impossible, only improbable. Saltwater has a way of degrading things, and sometimes bulkhead leak. Closed loop is not the correct term here because of the simple fact that there are bulkheads, and once in a great while they fail. A true closed loop system would NOT rely on drilling a tank, but rather using Schedule 40 or schedule 80 conduit to create a completely leak-proof closed loop system. The fact that you say "makes sure your cemented slip fittings are sound" implies that there is a possibility that they could fail. Like I said in my post to the OP...Be very careful or you will end up with a flooded room and an empty tank.

BTW...I've been a plumber for 14 years, even though I have a degree in Marine Biology...lol :hmm3:

It wasn't a flame.

I responded in context of the OP.

 

[Laddy]

IMO, you may want to reconsider drilling the bottom of your tank. If it's a glass tank, it's 99% sure its tempered glass on the bottom and it will burst into a zillion pieces. If its an acrylic tank, eventually the bulkheads will fail one way or another (salt creap, gasket breaks)

 

[coralcruze]

Ive been in the hobby for over 15 years and never had a problem with my bulkheads.

 

[Reefmonster]

Ive been in the hobby for over 15 years and never had a problem with my bulkheads.

That's great for you. I have been in it for just under 20 years and had bulkheads fail on two separate tanks, which is why I'm steering the OP away from them.

 

[Laddy]

Ive been in the hobby for over 15 years and never had a problem with my bulkheads.

Then I guess it'll never happen. :celeb1:

I've had saltwater tanks for 20+ years at this point, and have had a couple problems with bulkheads "down the road"........if they were at the bottom of my tank, the tank would have emptied. That's all I'm trying to say.

 

[Reefmonster]

It wasn't a flame.

I responded in context of the OP.

:thumbdown

The fact is that the closed loop is only as strong as the weakest point, which in this case is a drilled hole in the bottom of the tank. Saltwater degrades everything, including rubber & silicone gaskets, & sometimes bulkheads do fail, even if you have never had one do so. So it is not "impossible" :wildone: as you said. :eek2: