liner leaching

[kevin darcy]

Hi

I am considering buying a roll of 800 gauge high density polyethylene to line my growbeds, is 800 gauge heavy enough?  i'll be using pea gravel as grow media,a roll of (HDPE) is very expensive,  i want to use plastic or rubber pond liner but i was concerned about the plastic leaching into the water!,  does rubber leach?  would leaching in ap systems gb or ft liner's hinder AP farmers from obtaining an organic cert?. thank you.

[David Hart]

Thanks Kevin and Greener.......I thought I hit...'reply to this' when TC was talking about building tanks and using liners...(?)...The picture looks odd, without refering to TC's post.
I guess I'm practicing for old age....LOL

kevin darcy said:

Nice job david

Greener said:

nice looking tank David!

[Michelle Silva]

beautiful tank!

[David Hart]

Thank you Michelle.
I was blessed.....the liner and the posts were 'given' to me :-)

Michelle Silva said:

beautiful tank!

[TCLynx]

As a note about the Aquaponics Valves, they are made of a UV resistant plastic better than the older valves one might see for Irrigation. I got a look at some different models that had been left up on the roof in Florida sun for a year, the New Aquaponics one was still in good shape while the older types with the different plastics could be broken with a pair of pliers.

[Greener]

I was wondering if they were UV resistant TCLynx.. nice!

[Greener]

Thanks for the info Rupert. I looked up ASA plastic and see that the S stands for styrene.. on my list of no-no plastics. Is the manufacturing such that the Styrene is 'locked in' pretty well though? Would any concern of styrene leaching into the water (after prolonged use) be justified?

When you suggest to daisy-chain the beds, do you mean to have the outflow of a GB flow in to another (series)? I was planning on giving each GB water directly from the FTs to make the nutrient-dispersal across GBs more uniform, but I also like the idea of putting GBs in series to preserve the pump and save energy (longer off periods). If one connects GBs in series, do the GBs down the line still get enough nutrients for the plants, & solids for the worms?

[TCLynx]

I'm not sure but I think Rupe probably meant you can daisy chain the valves. Like if you had a 4 way valve (probably set as a 2 way) then it would alternate feeding two other valves. Of course that sort of daisy chaining would only be needed if you were installing a huge number of beds. If you start getting into an install that complex, it might be a long time between flooding of a particular bed. I'm currently using a 1/3 rd HP pump to a 1" valve and I'm easily able to flood 3 half barrels through that valve in less than 7 minutes. It does not necessarily have to be one outlet to one bed (depending on the size of the beds of course.) But the 1" valves can come in a 8 outlet model (I've only use the 4 and 6 outlet ones though) so there is quite a bit of flexibility as you figure out the design.

Having beds cascade might not work so well seeing as the first bed will get filled quickly but then drain slowly and the following beds will only get a trickle through and won't flood/drain. If you were to then add some sort of siphon or something to the following beds to achieve flood/drain, then you negate the fluctuation mitigation that the indexing valve affords.

As to the worry of lack of nutrient by the end of the line, I doubt that is as much of a problem as the over abundance of solids might be for the first bed in line.

I'm not personally worried about the plastic leaching from one valve especially in a product that is nicely UV resistant and going to be well coated in bio-slime anyway.

P.S. Bio slime does not seem to hinder these valves at all, I've actually noticed improved operation once they have been running long enough to get a slimy feel to the innards. Hard solid objects getting into them (like leaves, sticks, gravel, nuts, snails, screws, etc) can cause one to need to open them up to remove the debris.

[Greener]

Thanks TCLynx!

As much as I am enjoying this thread, I fear we've gone way off topic.. not sure how these things are managed in here..

[TCLynx]

Yea, I don't know. I suppose if Sylvia decides it needs to be split out to it's own topic, it could be done.

[kevin darcy]

Hi greener
You may have everything you need on liner leaching already, but you may find the link below interesting.
The stuff we should be worried about is called BPA (Bisphenol A )I am trying to find the safest gb liner or ft and pipework there is and i wont stop untill i find it, there are two reasons i want to do this (1) the safty and wellbeing of my family, as is everybodys first concern! ( if i feed my kids from an aquaponics system and in 10 years time one of them has symptoms of some kind, will i be able to rule out my growbed liner and pvc pipe work as the cause!) my answear is no, And (2) for aquaponics itself! let's just say that everybody involed in ap uses non (food safe) gb's and ft's or liners and in 10 years time somebody says (Hay everybody look what i found, proof that all non food safe plastic is (unhealthy), these aquaponics people have been poisoning us for years), that's a witch hunt that could take years to recover from.
As it stands i will be using hdpe fittings, pipe and liner, i will be lining my totes with HDPE and before i use any of these products i will be sending them off for independent testing.
If half of the things i read about BPA and the PVC pipe that most people use are true then for me the use of anything other than hdpe at best is irrasponsable and at worst a liability, or visa versa.
But please dont take my word for it, i wouldn't advise anybody about health issues as (i am not a health professional).
Here is one websites you could visit and you can use your own judgment to decide whats best for you and your family. ScientificAmerican.com go onto the site and type in BPA in the search box on the right hand side, I found it very interesting, might keep you busy for a while.
I read an article, it may have been on (sa.com) that said the US FDA have changed tack on BPA, after telling people for 20 years that BPA is safe, now they are saying it (needs looking at) I smell lawsuites, maby they do to.
I wouldn't and im sure you wouldn't put your health and safty at risk.
As it stands im afriad it's 'Caveat emptor' as far as buying plastic is concerned but i hear rumblings that this is to change and the onus in the future will be on big business (to prove their product is safe)... and not on the buyer.
Im also new to aquaponics but if i can help with anything i will do my best for you.
Anyway, best wishes and best of luck.


Greener said:

Hi everyone. This forum is great, I'm really happy to be here.

My understanding is that EPDM can work, but that some people have reported very long cycling times assumed to be due to the material. I also think EPDM is more likely to leach chemicals than LDPE (just my general understanding though.. EPDM does often smell like chemicals).

Until I read this thread I was planning on building my media-based system as wood-styrofoam-wood-LDPE liner, but reading the comments of termites/bugs eating the wood I think I must abandon that idea. I liked it because I'm finding it SO expensive to buy good-sized plastic or fiberglass troughs and tanks online (can anyone beat a food-grade 275 gal IBC tote for $90 + shipping?). When I think of the near guaranteed length of use I'll get from a plastic trough compared to possibly having to replace or repair the handmade tanks/GBs within just a couple of years, I'm more convinced that it's worth investing now in solid, food-safe, single-cast materials for the long run. It's going to be expensive (I want it to look nice) but so be it. We definitely have termites in our area so I'm really glad I read this thread! duh.. anyway thanks for saving me a LOT of trouble down the line.

I'm very curious to hear more about the PVC leaching issue, as I'm planning to use a lot of PVC (in the sun) in my setup. I'm planning on painting the exposed pipes to help fight UV (unnecessary?). I have been assuming that PVC is food safe, but can anyone provide a link to the evidence?

[Michelle Silva]

I have been running an organic produce buying club (Passion for Produce) for many years and have gone to great lengths to reduce my families risk to toxic chemicals (organic locally grown real foods, cloth diapered my babies,natural organic cotton/wool beds, good quality water filters, non plastic food containers etc.)over the years.

After months of researching trying to find different options that are being commonly used in AP systems, I feel pretty comfortable with the materials I'm using.. Until more sustainable options (the mushroom packaging.) are equally as available to replace what has been used (styrofoam rafts, vertical pots. etc) I will go forward feeling pretty confident it is a safe option. Even if there were leaching, the bioslime and all the beneficial bacteria can breakdown any toxic chemicals (even synthetic ones!) just as it can do in a compost pile. It's been proven this could have been used in the oil spill effectively. I used billboard material as my liner, which I believe is the same material as Dura Skrim, a material that is listed on the organically cerifited AP Friendly Aquaponics company lists under their FAQ that they use. I am happy to be recycling this as well as the fact that it has offgassed already. I think the benefits of being able to eat locally grown pesticide free produce that is freshly harvested exceeds the possible problems that Kevin has brought up. Many people in my community are very excited about it, including the Permaculutre guild and other very Eco minded citizens.

BTW, I contacted the mushroom packaging (for lack of better description) company and they are not creating a product to be used in a raft set up as of yet. Also, it's not meant to be submerged in water continuosly. The guy I spoke with told me he would send me a sample for me to test it out and if there was interest they would consider making it. I never received the sample.

~Michelle Silva

kevin darcy said:

Hi greener
You may have everything you need on liner leaching already, but you may find the link below interesting.
The stuff we should be worried about is called BPA (Bisphenol A )I am trying to find the safest gb liner or ft and pipework there is and i wont stop untill i find it, there are two reasons i want to do this (1) the safty and wellbeing of my family, as is everybodys first concern! ( if i feed my kids from an aquaponics system and in 10 years time one of them has symptoms of some kind, will i be able to rule out my growbed liner and pvc pipe work as the cause!) my answear is no, And (2) for aquaponics itself! let's just say that everybody involed in ap uses non (food safe) gb's and ft's or liners and in 10 years time somebody says (Hay everybody look what i found, proof that all non food safe plastic is (unhealthy), these aquaponics people have been poisoning us for years), that's a witch hunt that could take years to recover from.
As it stands i will be using hdpe fittings, pipe and liner, i will be lining my totes with HDPE and before i use any of these products i will be sending them off for independent testing.
If half of the things i read about BPA and the PVC pipe that most people use are true then for me the use of anything other than hdpe at best is irrasponsable and at worst a liability, or visa versa.
But please dont take my word for it, i wouldn't advise anybody about health issues as (i am not a health professional).
Here is one websites you could visit and you can use your own judgment to decide whats best for you and your family. ScientificAmerican.com go onto the site and type in BPA in the search box on the right hand side, I found it very interesting, might keep you busy for a while.
I read an article, it may have been on (sa.com) that said the US FDA have changed tack on BPA, after telling people for 20 years that BPA is safe, now they are saying it (needs looking at) I smell lawsuites, maby they do to.
I wouldn't and im sure you wouldn't put your health and safty at risk.
As it stands im afriad it's 'Caveat emptor' as far as buying plastic is concerned but i hear rumblings that this is to change and the onus in the future will be on big business (to prove their product is safe)... and not on the buyer.
Im also new to aquaponics but if i can help with anything i will do my best for you.
Anyway, best wishes and best of luck.


Greener said:

Hi everyone. This forum is great, I'm really happy to be here.

My understanding is that EPDM can work, but that some people have reported very long cycling times assumed to be due to the material. I also think EPDM is more likely to leach chemicals than LDPE (just my general understanding though.. EPDM does often smell like chemicals).

Until I read this thread I was planning on building my media-based system as wood-styrofoam-wood-LDPE liner, but reading the comments of termites/bugs eating the wood I think I must abandon that idea. I liked it because I'm finding it SO expensive to buy good-sized plastic or fiberglass troughs and tanks online (can anyone beat a food-grade 275 gal IBC tote for $90 + shipping?). When I think of the near guaranteed length of use I'll get from a plastic trough compared to possibly having to replace or repair the handmade tanks/GBs within just a couple of years, I'm more convinced that it's worth investing now in solid, food-safe, single-cast materials for the long run. It's going to be expensive (I want it to look nice) but so be it. We definitely have termites in our area so I'm really glad I read this thread! duh.. anyway thanks for saving me a LOT of trouble down the line.

I'm very curious to hear more about the PVC leaching issue, as I'm planning to use a lot of PVC (in the sun) in my setup. I'm planning on painting the exposed pipes to help fight UV (unnecessary?). I have been assuming that PVC is food safe, but can anyone provide a link to the evidence?

[kevin darcy]

Hi michelle,
That's fantastic news, " Even if there were leaching, the bioslime and all the beneficial bacteria can breakdown any toxic chemicals (even synthetic ones!) " so even if some -say- nitrates make it past the plants and back to the ft's some plastic would too but the amount that made it back would be negligible, (although i dont believe any amount plastic should be in the human body) so you said the beneficial bacteria can breakdown "any" toxic chemicals (even synthetic ones!) " if memeory serves- the beneficial bacteria in ap systems are called heterotopics, so youre saying that heterotopics can break down any toxic chem's, (even systhetic ones) thats fantastic! do you have a link to the evidence that told you that beneficial bacteria breaks down leached plastic? what does it break down into?.

Just one more thing michelle, you said " I think the benefits of being able to eat locally grown pesticide free produce that is freshly harvested exceeds the possible problems that Kevin has brought up" so basically that sounds like youre sayin that if we eat "locally grown pesticide free produce that is freshly harvested" injesting 'possible' leached plastis would be- -ok? quote " exceeds the possible problems that Kevin has brought up" please clarify, and thank you for all the info.
best wishes.

Michelle Silva said:

I have been running an organic produce buying club (Passion for Produce) for many years and have gone to great lengths to reduce my families risk to toxic chemicals (organic locally grown real foods, cloth diapered my babies,natural organic cotton/wool beds, good quality water filters, non plastic food containers etc.)over the years.

After months of researching trying to find different options that are being commonly used in AP systems, I feel pretty comfortable with the materials I'm using.. Until more sustainable options (the mushroom packaging.) are equally as available to replace what has been used (styrofoam rafts, vertical pots. etc) I will go forward feeling pretty confident it is a safe option. Even if there were leaching, the bioslime and all the beneficial bacteria can breakdown any toxic chemicals (even synthetic ones!) just as it can do in a compost pile. It's been proven this could have been used in the oil spill effectively. I used billboard material as my liner, which I believe is the same material as Dura Skrim, a material that is listed on the organically cerifited AP Friendly Aquaponics company lists under their FAQ that they use. I am happy to be recycling this as well as the fact that it has offgassed already. I think the benefits of being able to eat locally grown pesticide free produce that is freshly harvested exceeds the possible problems that Kevin has brought up. Many people in my community are very excited about it, including the Permaculutre guild and other very Eco minded citizens.

BTW, I contacted the mushroom packaging (for lack of better description) company and they are not creating a product to be used in a raft set up as of yet. Also, it's not meant to be submerged in water continuosly. The guy I spoke with told me he would send me a sample for me to test it out and if there was interest they would consider making it. I never received the sample.

~Michelle Silva

kevin darcy said:

Hi greener
You may have everything you need on liner leaching already, but you may find the link below interesting.
The stuff we should be worried about is called BPA (Bisphenol A )I am trying to find the safest gb liner or ft and pipework there is and i wont stop untill i find it, there are two reasons i want to do this (1) the safty and wellbeing of my family, as is everybodys first concern! ( if i feed my kids from an aquaponics system and in 10 years time one of them has symptoms of some kind, will i be able to rule out my growbed liner and pvc pipe work as the cause!) my answear is no, And (2) for aquaponics itself! let's just say that everybody involed in ap uses non (food safe) gb's and ft's or liners and in 10 years time somebody says (Hay everybody look what i found, proof that all non food safe plastic is (unhealthy), these aquaponics people have been poisoning us for years), that's a witch hunt that could take years to recover from.
As it stands i will be using hdpe fittings, pipe and liner, i will be lining my totes with HDPE and before i use any of these products i will be sending them off for independent testing.
If half of the things i read about BPA and the PVC pipe that most people use are true then for me the use of anything other than hdpe at best is irrasponsable and at worst a liability, or visa versa.
But please dont take my word for it, i wouldn't advise anybody about health issues as (i am not a health professional).
Here is one websites you could visit and you can use your own judgment to decide whats best for you and your family. ScientificAmerican.com go onto the site and type in BPA in the search box on the right hand side, I found it very interesting, might keep you busy for a while.
I read an article, it may have been on (sa.com) that said the US FDA have changed tack on BPA, after telling people for 20 years that BPA is safe, now they are saying it (needs looking at) I smell lawsuites, maby they do to.
I wouldn't and im sure you wouldn't put your health and safty at risk.
As it stands im afriad it's 'Caveat emptor' as far as buying plastic is concerned but i hear rumblings that this is to change and the onus in the future will be on big business (to prove their product is safe)... and not on the buyer.
Im also new to aquaponics but if i can help with anything i will do my best for you.
Anyway, best wishes and best of luck.


Greener said:

Hi everyone. This forum is great, I'm really happy to be here.

My understanding is that EPDM can work, but that some people have reported very long cycling times assumed to be due to the material. I also think EPDM is more likely to leach chemicals than LDPE (just my general understanding though.. EPDM does often smell like chemicals).

Until I read this thread I was planning on building my media-based system as wood-styrofoam-wood-LDPE liner, but reading the comments of termites/bugs eating the wood I think I must abandon that idea. I liked it because I'm finding it SO expensive to buy good-sized plastic or fiberglass troughs and tanks online (can anyone beat a food-grade 275 gal IBC tote for $90 + shipping?). When I think of the near guaranteed length of use I'll get from a plastic trough compared to possibly having to replace or repair the handmade tanks/GBs within just a couple of years, I'm more convinced that it's worth investing now in solid, food-safe, single-cast materials for the long run. It's going to be expensive (I want it to look nice) but so be it. We definitely have termites in our area so I'm really glad I read this thread! duh.. anyway thanks for saving me a LOT of trouble down the line.

I'm very curious to hear more about the PVC leaching issue, as I'm planning to use a lot of PVC (in the sun) in my setup. I'm planning on painting the exposed pipes to help fight UV (unnecessary?). I have been assuming that PVC is food safe, but can anyone provide a link to the evidence?