Z-Flow vs. Drilling

[perrymedik]

I have a 125g fresh water tank that I am researching turning into a Salt Reef/fish tank.

My current point of focus is filtration. I know I want to use a sump/refugium. What I am trying to decide is the best way to get the water to the sump.

What are the advantages/ disadvantages of using an over the back overflow or drilled overflows.

Obviously there is a risk being taken when attempting to drill a tank. But the necessity of taking that risk will have to be determined later after I can find out the pro's and Con's of each method.

All input would be gratefully accepted!

Thanks in advance!!!

 

[jsoong]

my 2 cents's worth:

Drilling is better - easier plumbling, looks better, don't have to worry about siphons quitting.

But, I settled for an over the back - too chickened to drill a tank!

 

[Sparky]

Me too. Chicken here.

 

[Overstocker]

Next to impossible to spill/overflow (can't think of one but there might be a way)your tank with a drilled tank and has less maintenance worries (air bubbles in over flow 8O )

If you want an idea what it would be like if your siphon quit and you overflowed several gallons on to the floor.... just grab a gallon of milk and pour it on the floor near your aquarium, repeat as necessary. Leave it for several hours (cause you won't be there when/if it really happens), then commence the clean up process. Now the smell a few days later won't be exactly like your aquarium water nor will you get the neat crystalline structure from the salt but you will get to have allot of fun 8)

 

[ltimberl]

At one point I had two 135's going. One was pre drilled, and the other had the overflow. The If you lost suction the overflow was a pain to restart. If you decide to go with the overflow, leave enough room on the back side of the aquarium for you to stand behind. You can't start the sucker by leaning over the top.

 

[first-timer89]

i was just about to post the same pole

 

[WhiteCloud]

Still a newbie...but if you were planning a reef tank....a 10-15 turnover rate per hour is recommended.

On a 125gallon tank that is 1250-1875 gallons per hour. Most predrilled/built in overflows allow for 600gph..which would be about bear minimum if you had 2 built in overflows.

Overflow boxes can handle 900 gph...and with 2 boxes...you have 15 times turnover in your tank.

1 small drilled hole near the top of your return (just under the water surface) will prevent any spilling over your sump as it will break the suction as soon as the water is drain passed a small drilled hole on the return.

Now if you can drill more than 2 holes and drill them bigger for more flow...I have no idea....but I just wanted to offer those thoughts

 

[BillyZ]

I'll just add that the 10-15 times of turnover does NOT all have to go through your sump. IMO, you don't want that all to go through your fuge, you want a slightly slower rate through. The 10-15 times should be the full total movement, from the sump return, and PHs, closed loops etc. So on a 125, two 600GPH holes and a couple powerheads and you're doing just fine.

 

[dustybrannum]

On my 180 i have a mag 36 return pump from my sump and an over flow with 7- 1 1/4" "U" tubes and 2 2" drains. This has kept up so far. plus 3 295gph ph's in the tank. my fuge is fed from my sump with a mag 5 at 3 feet head. so im looking at around 3500-4000gph flow taking away for head and elbows in my plumbing therefore a turn over of around 18 times an hour yet before i had the same setup with a mag 24 and had cyano form, so this should cut that out. im redesigning my hang on over flow so that it will look better and work better.

 

[swissfish]

On my 80G i have a 2" pipe sticking into the tank wich is handling my drain, return and power cords. Clean and idiot proof, just the way I need it.