Backyard Aquaponics
A place to discuss aquaponics

nice, can't wait to see some pictures of the process of building your grow beds with ferro cement. My research so far is pulling me into that direction as well.

I will try to update this week on progress. The growbed mold is made and we begin to plaster on Tuesday.

Are you using PVC pipes as drains? I've seen some 1 m high ferro cement tank plans with a drain in the bottom corner. I'm wondering if the cement will bond to the PVC and make the connection watertight. I'd like to put a drain in my ferro cement tanks so they can be easily emptied if needed.

If it is just a drain you want, they sell shower drains here made of aluminum that adhere just fine to concrete shower floors. They have an aluminum plug as well. Not sure if you could get them there.

Probably what I will do is put pipe in the cement to form the hole. then put my fittings through the hole and seal with silicone or Silkaflex. I question whether pvc will form a good fit but I probably will try on one of them to see.

On the tanks I have Here. I cemented the pvc drains right into the bottoms of the grow beds and so far they are working just fine. No leaks at all. But a fish tank is deeper and there would be more pressure. So we try. If it works we keep doing it, if not, we try something else.

As promised I began work on the ferro cement grow beds. I covered the mold with screen after paining it to keep the cement from sticking to it. I need to have another coat of cement plastered on in the morning to finish it up. I figure in two days I will pull it off the mold and see if the project was successful.

So far on this particular grow bed I have spent $17.00 US. With labor I will probably have about $25.00 if all goes well. It is costing more than I would have liked but it is the first go around.

Sorry for the pic quality. It would have been hard to move this work in progress out of the afternoon sun.

We are, as I write this putting the final coat on the first Grow Bed. I am hoping to remove the mold tomorrow. It seems to have set up nicely overnight.

Good stuff DT, keep the updates coming

final coat is on the grow bed. Waiting for it to dry. The "P" word again. I will show a pic of finished coat and in a day or so, I will take it off the mold and give you the results.

Looking good there DT. You ever get a hold of Franklyn he would be real interested in this and as he works with world vision might be able to get some funding for you. I can't wait to get back to indo as we are trying to make some large ferro beds

mixed results on the grow bed. It really looks nice. The cement got a little thick in spots which mad the box a bit heavy for two people to move around but that is not a real issue. What is, is that I can't get the mold out of the box. The sides have come undone but not the bottom. I hate to have to ruin the mold to get it out but I may have to and give the next one a bit more angle and a better parting compound.

Updates to follow. I am also looking into a fiberglass option. Unfortunately I have no idea where to start investigating but I will trudge on.

Maybe if you added a few straps to the mold to give you something to pull on? Or maybe a layer of plastic film between the mold and concrete?

Dt, we used to use 2nd hand oil for concrete molds, I understand that this may not be an option because of contaminants but leads to the idea of 2nd hand cooking oil maybe?

Actually that is what we used. I think the problem was that the wood was not smooth enough or maybe air suction. I may try drilling a hole or two. Something easy to fill back in later