Simply Koi and More Koi

I have a 4 bay filter system built from concrete - it's around 20 years old. You may have seen another post about it.

There are some bricks in one of the chambers which are used to support some filter dividing plastic which directs the flow of water through some biological media.

Are submersed bricks (in the filter system) dangerous for fish? Do bricks have toxic chemicals which could leach out?

Adam.

Hi Adam

Not that I'm aware of, they're usually made of clay and that's what's at the bottom of most mud ponds. Anyway, I'd have thought that anything that may leech out of them will have done so after 20 years!

Cheers

Bob

If you're really concerned about it then why not switch them for class A engineering bricks? They are totally waterproof and I've had some of them in my pond and stream for years with no ill effects.

bricks can be very dangerous in koi ponds or filter bays..IF they fall on fish...usually a "ton of bricks" falling on a koi can be quite distressing