Wants a closed loop

[acid_burn]

When I setup my 120gal I didnt drill for a CL, currently I use a couple of Rio ph's for circulation. I want to get as many of the ph's out of the tank as I can. I know I cant drill the back of the tank now but I seen something in another forum where they drilled the tops of the acrylic aquarium and ran the CL over the top. Has anyone besides him try this before? My plan would be to run an outlet at all 4 corners and one in the middle. Would there be any advantages/disadvantages to running it this way? Let me know if you would do it this way, what equipment you would use, how you would spice it up to work better, cause if I do this I only want to do it once.

Heres a pic of his.

Thanks,
Rich

[fishfreek]

The returns is not the biggest issue with the closed loop but the supply line going to the pump would be. A close loop has the supply line going directly into the pump and the return comming directly out of the pump. Thus an entierly closed water circulation system. If you dont have the supply via a bulkhead below the water line then you will need to setup some kind of syphon and you would need to make sure it was free of air as air collecting in the close loop will end up causing microbubbles to be injected into the tank.

[BillyZ]

this is similar to what i've done with my 55 gallon. I have a single mag 5 pump that draws water through a PVC pipe that goes up over the back of the tank, down to the pump, then up to a T that splits the return to two outlets that hang just over the back of the tank. I do occasionaly (but rarely, maybe once or twice a day) get bursts of micro bubbles, but they don't really hang around very long. I'm pretty happy with the set up but I would deffintely suggest making sure the PVC is well sealed and also suggest putting a pre-filter sponge over the PVC intake. I used the one that came with the mag-5 pump I purchased.

[acid_burn]

My plan was to draw water from over the top with a pvc pipe running down the back(inside) of my tank and drill it full of holes to draw the water in. If I painted the pvc pipe with the purple primer would it have to sit and cure before I put it in the tank? What size/brand pump should I use? I will have 5 outlets in the tank one at each corner and one in the middle. I would rather go overkill on the pump than fall short and just install ball valves on all the returns. I'm getting excited about it...cant wait to get all the ph's off the glass.

Thanks,
Rich

[fishfreek]

Drawing water over the top will be fine but you will probably need to prime the pump. Since you will be pulling water up and over the top of the tank should to much air get into the intake the syphono will break and the close loop will run dry. Most pumps are not designed to operate dry for more than a breif period of time.

I would not paint the pipe with pvc primer. Instead use plastic rated spraypaint or something like that. When it comes to sizing the pump you have to know what kind of flow you want. Then pick something a little larger to compensate for all the plumbing joints.

[Mr Burns]

Originally Posted by fishfreek

I would not paint the pipe with pvc primer. Instead use plastic rated spraypaint or something like that.

i wouldn't even do that. using RIT Dye is by far the best way i've seen used to color pvc and you'll never have to worry about paint or harmful chemicals getting into the water.

[Hold Anchovies]

Rit dye? Cool! I have been looking for a way!