Drain Seal for Barrelponics Growbed - how hazardous is brass?

[Josh Metten]

I have been struggling with getting a good seal on the drain holes in my grow beds, which are one 55 gallon plastic barrel split and opened up clamshell.  I'm trying to set up a bell siphon so I drilled holes in the bottom (was the side so it is curved) of the beds.

 

1st attempt we used bulkhead fittings which cracked due to over tightening, but they were not sealing properly, I'm guessing due to the slight curvature of the barrel.

 

2nd attempt was successful but we used 1'' threaded brass nipples, which I am now realizing are not good to have in an aquaponics system.  My question is what is the hazard of having brass in an aquaponics system and what other options for this setup would work?

 

Should I order uniseals or were bulkhead fittings the way to go?

[TCLynx]

I would say uniseals, they are cheaper and far more likely to seal properly.  what size holes did you drill?

 

[Josh Metten]

I drilled 1 1/4'' holes then heated the plastic with a heat gun and threaded in the brass nipple.  I've tested both beds and they don't leak at all.  Next time I'd like to go with uniseals but I am hoping I can keep what I have intact, is the brass going to mess up my system or kill the fish?

[TCLynx]

brass contains copper and over time and in an acidic environment may corrode and leach copper into the water which can be bad for the fish if it builds up enough.  What kind of fish are you growing?  If you can keep the pH near neutral (7) you might slow the leaching.

Also over time as it corrodes it could start leaking.

 

a 1 1/4" hole (provided you didn't melt it too much bigger) will work with either 1/2" or 3/4" uniseals so if you were to order some uniseals then you could probably swap when you get them, just unscrew the current fitting and then pop the uniseal into the hole and use some slimy water to lube the pipe and push it in.  It is usually fairly easy to push 1/2" or 3/4" pipe through a uniseal through a barrel.  It is the larger uniseals that are often more difficult.

[David Waite]

Josh if you have the brass or bronze nipple in your system and plan on keeping it. Cover the water side with 1/2 in of aquarium silicon to slow electralisis. You will be ok. The brass isnt in your tank where dissimilar components will trigger electralisis. Not the preferred but probably wont hurt ya. Let the silicon set up for 48 hours before you add water. Use only aquarium silicone.

[Johann]

A must read,http://en.wikipedia.org/wiki/Brass

Brass can contain: copper, zinc, aluminum, lead etc ......this could be very bad for an recirculating system, since these metals are just increasing there concentrations over time in the system and plants may absorb some of it and it could end up in your stomach.

[Dukie Dixon]

Thank you! My fish started to die when I added my float, and it contains brass. I am replacing it now.