Rainwater tanks - Plastic vs Galv

[Mansfieldman]

As is the trend I am wanting to put in a Rainwater Tank. Galv is traditional put plastic more fashionable.. Any pros and cons? Which offers the better water quality?

[bsrlee]

Gal will eventually rust out, but its easy to patch if some ding-a-ling shoots a hole in it. I think it will taste the best, but that's just my old memories - if you like plastic chemicals, you can get paint-on plastic tank liner from some of the fiberglass/polyurethane manufacturers. If you don't handle it properly during installation, you can pop the bottom seam & get a B@#&%(d of a leak that is a pain to fix - make sure you have some skinny kids around to help DAMHIK.

Plastic - well it depends on the type - can be affected by UV and go brittle. When they crack or have holes shot in them, they will be more difficult to patch than Gal, if not impossible. Most of the plastic water tanks I have seen were intended for watering gardens, and plants don't complain about the taste of plastic solvents/plasticizers in their water.

You pays your money & you makes your choices.

[Gumby]

I have a plastic tank. 500 gal (2200L) and it's fine for washing the car and watering the garden. Consider how long plastic lasts under ground or in a tip - bloody ages. The water tastes OK too.

Cheap, easy to handle when installing, it's the way to go IMHO.

[DavidG]

Plastic for the smaller tanks upto 20,000L
Metal sides with bladder liner for 20,000 to 50,000L
Concrete with or without a bladder for over 50,000L

That was from one set of costings I did but it may
vary for your area.

[Wood Butcher]

The poly tanks that are made up here are UV stabilised plastic, have anti-bacterial properties and can be repaired on site if they are damaged. My old boy just had his 15yr old poly tank cleaned out last week and it is as good as the day he bought it.

His neighbour has recently bought 2x10,000 gal tanks and before he had a chance to install them, one got picked up in a wind gust and was impaled on a star picket. The manufacturers came out the next week (after he had recovered it) and repaired the damage with a gaurantee on the repairs.

Would go for poly anyday especially given the huge range of colours and shapes that they are available in.

[DJ’s Timber]

My last house had a 1000 gallon which is exposed to the sun all day long, the water tastes fine and the tank is still in good nick. I think the landlord said it was there for about 4 yrs before I moved in.

[masoth]

My opinion - it depends on what purpose you intend for the water, and where you propose mounting the tank.
"Food quality" tanks are available ......... various shapes are available (dividers to decorate the garden) ........ under the house, out of sight bladders.
Talk to a supplier of your needs/wants and be guided by the professionals.

[outback]

Easy Peasy.

Plastic.

Gal tanks rust, I am waiting to replace one I installed about 18 years ago, and it is completely kangaroo edward. It has a heap of rust holes around the top water line, as for many years we didn't use much water from that tank.

I have a plastic tank installed soon after the gal one, still going strong, I can't see why it will need replacing by me.

As others have said, you can get diffrent colours and whilst more expensive, funny shapes to get into tight places.

[Christopha]

FIBREGLASS! I have three x 4000 gallon fibreglass tanks, 2 at home which replaced the Galv tanks which barely made 20 years and the 3rd is at the beach shack. The taste is fine, no hint of any taste other than pure sweet water and they look pretty good compared to poly tanks which usually seem to have strange bulges, huge corrugations and strange 'strusions. Fibregalss is relatively simple to repair and I am told the UV isn't really a problem.

[Zed]

we have a 2000L colourbond from bluescope and its quite fine. its still new so time will tell. We use it for the garden and topping up the pool and its ok for that. I reckon if your gunna use any tank water for drinking or cooking it doesnt really matter which use use so long as you filter it for the bugs (I reckon a good charcoal filter is the go).

[TEEJAY]

If you want to purify the water recommend you get the silver impregnated ceramic filter inside the water filters you get at health stores etc. The silver in the ceramic kills the bugs the ceramic is fine enough to stop the coloids (sinking floaties, particles) and remove any chlorine in water. Charcoal is purely to remove particles - won't kill bacteria not sure if it removes chlorine either - chlorine will disipate in a container if left to air or breath.

Locally they are talking about re-cycling water into the water supply systems. We will not drink recycled sewerage water - I don't care how good they say they can make it - so be sure we will use rainwater cycled through a purier in our house for drinking.

We got on the weekend a 10 000l poly tank. As mentioned above the tanks are food safe plastic and won't have the plastic flavour.

[silentC]

You'll find it hard to get a plain gal tank these days. Steel tanks are now made from Aquaplate. It doesn't rust.

In the sizes that plastic and steel are available, the main drawback of steel is that it needs a good solid base, like a slab. Plastic tanks can sit on sand. You have to add the cost of a decent stand or pad for steel.

Don't really know of any disadvantages of plastic, never having bought one myself. I have a 5,000 gal. steel tank off the shed. My brother in law makes them, so I got it cheap, otherwise I probably would have bought plastic.

Someone told me that the water heats up more on hot days in plastic but that could be crap.

[Wood Butcher]

Someone told me that the water heats up more on hot days in plastic but that could be crap.

I know that at my old work we had a 5000gal poly tank that we used to top up our water bottles from. Even on the hottest days the water was cool.

But, the tank was a light cream colour too. If the tank was a darker colour then I agree that the water would heat up.

[MurrayD99]

We have 2 x 25k litre concrete tanks in ground and a 25k litre plastic above ground... You are not supposed to bury the plastic ones according to the manufacturer. I don't think galvanised iron tanks go very big. How big a tank are you thinking about?

[silentC]

I don't think galvanised iron tanks go very big

Biggest one my BIL makes is 5,000 gallon. I haven't seen plastic ones any bigger than that around here, but that doesn't mean they aren't available. They'd be getting a bit big to transport though.