Plan for 12+ hour pumps shutoff to fix leak

[Spar]

I have a leak in my external calfo overflow and need to run silicone around the leak. i have conisdered aquamend or waterweld, but feel silicone will be the best bet especially on a smooth surface.

i will need to shut off my return pumps during this time.

for the main DT portion (450g) i will be running my 2 MP60's, so will/should be plenty of flow for that period to keep it oxygenated.

for my sump, i have a strong 4-valve air pump to throw airstones into each compartment.

lights will be off during this period as am doing it over night.

anything else i need to consider and/or prepare for to make sure no bacteria or critter die off happens?

[KafudaFish]

WC water?

[Spar]

Originally Posted by KafudaFish

WC water?

yep, i will have 150 gallons mixed just in case. Plus 150 gallons RO/DI ready to mix after. Benefit of having 200g vats used for storage

[johnike]

Sounds well planned.

[Spar]

what about stale water sitting in pumps, tubing, etc? is 12-15 hours not enough to worry about?

also, on that note. think 12-15 hours is long enough for silicone to cure to the point where it won't cause toxicity to the water passing by it? usually it hardens pretty quick.

and by the way, this leak is like 1 drop every 5 seconds, nothing massive by any means. i am betting that this pump shut off period is unnecessary, but I am not willing to risk it.

[gardy]

You could get some PVC and make a bypass of the overflow drain, lowering the water level a bit first so you still have a drain and return without the overflow

[DasCamel]

Sounds fine, main thing is flow and surface water agititation. 12-15 hours, no biggie.

[tkeracer619]

Whats leaking? The glass? I assume you are going to run a new internal seal on the overflow box.

Silicone cures faster in warm humid environments. I would try to apply the thinnest bead you can get away with.

[Sethjamto]

Your plan sounds perfect to me, especially with the 150g's of SW on standby if needed. The two MP60's and airstones in the sump will handle it all. You may consider moving a heater to the DT during this time as well just in case....not sure how cool you run your A/C.

[Spar]

Originally Posted by tkeracer619

Whats leaking? The glass? I assume you are going to run a new internal seal on the overflow box.

Silicone cures faster in warm humid environments. I would try to apply the thinnest bead you can get away with.

Not sure what material it is, but it is the overflow box itself that is leaking. Here is a picture of it originally (well prior to leak). it is leaking on the outer side of the box (not where it is connected to the tank). it is such a slight leak that I am sure a thin layer would do. any i have no shortage of hot and humid here in Dallas (ignoring the recent cold fronts)! Temp should be fine, but I can easily run one of my 500w heaters up to the top if it starts to get low. i've never seen the temp drop below 77 though.

[gardy]

I'm also not sure if I would be comfeterable only letting it cure for 12 hours, but in this situation I don't see another way

[Spar]

Originally Posted by gardy

I'm also not sure if I would be comfeterable only letting it cure for 12 hours, but in this situation I don't see another way

i was originally planning for 24 hours. but i talked to the manufacturer of my tank and they said 12 is enough. regardless, i will be doing closer to 17 hours. lights out to lights on period. so meeting in the middle at least.

so little water will be in contact with the leaking area, and with 450g volume, dilution will be my friend.

will update after i finish. doing this Friday night so i can be around to monitor.

[Spar]

what about this product instead?
http://www.durapower.com/Pipe%20&%20Hose.htm

i mean, really i am just looking for something to block the water exit; there is no pressure at all pushing out.

[Vinny Kreyling]

Years back I used this product on a cpvc line into the tank from the pump & never shut it off.
Phenoseal
Google it & you can read the MDS sheet
Comes in Black

[tkeracer619]

Looks like acrylic to me. Call and ask them but if it is I would use some water thin weldon to fix it. Should be able to turn the tank back on within an hour.