Everyone I talk to tells me that there is no product on the market that can be applied to concrete as a non-toxic waterproofing agent.
Can anyone shed some light on this?
How do these folks like "Morningstar" who build concrete tanks in 3rd. world countries solve this problem?
Have you looked at thoroseal FX100? Also ...what reinforcement did you use in your tanks? Mesh? Fiber? Rebar? I am looking at using a pre-made septic tank as my sump. Any thoughts?
Thanks Bill...Great info....Sounds like the rubber is the ticket....all things considered.
Bill Swearingen said:
We used to use Thoroseal. The problem was it tends to brake down within acouple of years. Aquatic environments are very hard on this product. If you use any rubber product, be sure to acid wash your tank first with muratic acid. BE CAREFULL!! Ware protective clothing ang a respirator! With deli gent preperation Ruberize It should last much longer. The other problem with Thoroseal is it is not inert and will raise ph as it brakes down.
There are paint on 2 part liquid rubber liners that i have used on old farm ponds but i do not know if it is food grade.
I visited a commercial tilapia breeder who makes all his tanks from concrete, and does not seal them with anything. When the pH falls, it leaches the lime out of the concrete, buffering the pH. He has to resurface his tank every few years because of this.
If the pH is neutral it shouldn't leach from your tanks, so he adds lime to try to keep his pH up. Despite this he still resurfaces every so often, although I don't remember how often.
I've used paraffin wax before with no problems in an aquaponic system.
I have used rubberizit on my grow bed. Last year when I took down my system, I fiberglassed the inside of my wood grow bed then used a paint roller to apply the rubber. After letting it cure for 7 days, I replaced the gravel and flooded the bed. No leaks so far. The system has been down for the last year with the gravel sitting in the GB. No problems so far. I'll be fiberglassing and rubbering my FT and ST this spring to start the system back up. I'll let you know how the rubber has held up over the winter.