As suggested, I'm adding blog post below to "forum"..still need to learn how best to use this site.Thks.
Can anyone advise what the difference is between using Dow blue boards and the white 2" styrofoam at Home Depot. Do the dow blue boards need to be painted? I don't know if I would ever try to be "Certified Organic" but I would want to do what is safest.. Does it make a difference? Thanks.
Just read this post and am wondering how the sealed PVC worked out? I am going to try that also but don't know if 1/2 or 3/4 would be the correct size.
Where do you get old billboard material?
Ok, here I go on a new experiment!
I now have a big raft bed to experiment with. Well it's not plumbed in yet and I notice the used billboard liner leaks a little where small abrasions or pin holes have damaged it but are for the most part too small to really see. Not sure if it will work long term but I'll try testing it out for a bit, I can always turn it into a bed wicking bed for dirt gardening if I decide the raft method doesn't work for me.
So does anyone know exactly what kind of paint is food safe for the rafts?
I'm going to experiment with a few different possibilities for rafts. The bed is about 36 inches wide so I figure a 32 inch wide raft would be appropriate which is conveniently an 8' long board cut in thirds. (the bed is long enough for six 4' long rafts at that width.)
I'm still a big fan of using rayon mop string wicks in net pots to allow for starting seeds directly in net pots and I've also found that a peat pellet dropped onto the wick in a net pot will stay moist enough to keep a seedling going till it's roots reach down to the water. I've found that the peat pellets stay nicely moist using capillary fabric with an end hanging into a trough of water so this is a great way to start lots of seeds in a small shelf space. I'll be testing other seed starting methods on the capillary fabric as I can.
I do like the idea (in my system since I've got plenty of bio filter and solids filter in my grow beds) of suspending the rafts above the water so that I don't need to add lots of extra aeration to the beds. However, my bed construction won't support too much weight on it's edges or allow for easy sliding of anything resting on those edges so I still need to figure some way to FLOAT the plat supports. I might try a square of sealed up PVC pipes to support a board with holes. I also want to sort out some way to float the rectangle seed trays for growing baby salad mix ans such (this sort of use might be the most useful to me.)
Looking for other creative ideas too.
Cosmo gave me one of the old liners, I don't remember who he called to get it. It leaked though so I don't really recommend them.
Im researching about Dow styrofoam and I find this:
what do you think?? do you trust Dow?
New Flame Retardant for Polystyrene-Too Much Like the Old?
PBT Chemicals-Persistent, Bioaccumulative, Toxic
New Flame Retardants Less Toxic but Still Persistent, Says EPA
No, didn't find any alternative that would work easily.
I just reread my previous post and have to laugh. I didn't realize it was perlite floating that I was seeing in the raft tanks and not the styrofoam...the reg styrofoam boards are holding up pretty good and none were painted, but I do think I should have painted them right away..it really helps to protect them..still working on getting them all done..
I think wood has been used by others on this board (with a gap, which I guess you then need to make sure net pot or whatever you use can touch water and wick up)..maybe it was Chi from Hawaii who might have had that...may be a good alternative if one won't be lifting the rafts off system to harvest.
Let me know what you find out..thanks.
BTW, don't use perlite media..I use a little mixed w/ coco coir.. the perlite wasn't making it back to the fish tanks but not sure if it possibly will still affect the fish