Fresh Water Tanks: Polyethylene vs. ABS?

[DenverAaron]

I am looking into replacing my fresh water tank and system (I have a '63 Safari). I was curious if anyone has used an ABS tank instead of the standard white polyethelylene tanks? I can get an ABS tank for about half the cost, and I can modify the outlets myself with standard ABS solvent instead of having to weld the plastic tanks. Does anyone know the pros/cons of either system?

Also, how many water filters do you recommend installing? One in between the tank and fill hose? One in between the city hookup? And a strainer before the water pump?

Many thanks!

[byamcaravanner]

I can't give you a comprehensive comparison... but I have read that ABS tanks do not let light in, thus helping to prevent algae growth... a plus in my book!

[Kajtek1]

I just bought bladder tank for my 65 Safari
MariSafe - Boating products and services designed to make you safe, smart and secure
They sell them on ebay for $64. I am using bigger model of that tank in my motorhome for 3 years and love it. The icing is, that if I decide to go camping on my boat for a week, I can use the tank there as well and just roll it for storage when water is used.

[Silvertwinkie]

My wife works for a plastics distributor. They basically buy the pellets from the oil companies and have a small R & D Department for basic plastics testing and such. I ran this question by here and here is her response:

Hands down, Polyethylene. It has better chemical resistance and will be
best for all the "stuff" it will be in contact with. The product would
be similar to that which is used to make 5-gallon pails (buckets). Low
melt, medium to high density polyethylene.

[markdoane]

Whichever you use, be certain it has NSF approval. Usually this is not an issue with polyethylene tanks, but NSF approved ABS tanks are less common.

It's due to limits on extractables. Not an issue with PE; more difficult to attain with ABS resins.

I use polyethylene. As Silvertwinkie said, there's never an issue with polyethylene.

[DenverAaron]

Hey, I love that idea about the bladder! Sure you have to protect it, but you can do that by creating a safe compartment for it. And when you want to winterize it, all you have to do is drain it, remove it, and hang it above the bathtub! Love the idea!

I checked on the website and it says that the inlet is 1.5" and the outlet is .48". Are these dimensions standards for attachement sizes?

Can anyone think of a reason why oversized camelback for my silver bullet would not be a good idea?

[DenverAaron]

Also, what about the filters question. How many and how often? (see my original thread for the complete question).

Thanks!

[byamcaravanner]

This is the one I plan to use

Valterra Fresh Water Tank

[markdoane]

Originally Posted by DenverAaron

I checked on the website and it says that the inlet is 1.5" and the outlet is .48". Are these dimensions standards for attachement sizes?

The inlet and outlet are metric, and you will have trouble finding fittings.

Just order the inlet/outlet accessory kit, they have hose barbs which you can use to convert to US fittings.

[Kajtek1]

The bladder tanks have barb connectors. One will fir 1.5" hose, the other 1/2" hose. In my motorhome I am filling up the bladder via the T on the smaller hose and the top is capped, preventing air access. Having water in in constantly, I never had algae problems. The only filters I am using in my RV is the washer-mounted filter on the city connection. Everything else in the RV is kept clean, so no filters necessary.
The tank has very durable exterior fabric, so it doesn't need any extra protection. Just make sure you have no nails sticking out in the compartment. I hope to use the corners of my trailer for extra capacity, Maybe will not get full 40 gallons in the 12x12" cross section, but hopefully more than original 30 gallons. Will post more info when install tank in about 3 weeks.