Rain Water Tank Filter

[mabrungard]

A carbon filter is not really intended to 'filter' particulates. It is intended to adsorb contaminants and packing more carbon into that cartridge is a way to get more treatment capacity. While I won't knock anyone's decision to include carbon treatment for their rainwater, its probably not really needed.

However, proper filtration is essential for bringing potentially biologically-contaminated water up to potable standards. I'm betting that water off your roof isn't very cloudy or turbid, so the sediment load is likely small. Since you probably don't want your filtration system clogging prematurely, having a cascade of filters is wise. Starting coarse and working your filtration finer, is the way to go. Starting with something like a 5 or 10 micron filter is appropriate. However to virtually assure that biologic material don't pass into your drinking water, including a filter with a pore size rating of about 0.5 micron is highly recommended. Pretty much all biologic materials are larger than that 0.5 diameter and they should be filtered from the flow. The water is essentially biologic-free.

To assure sterility, including a UV filter could add peace of mind. However, its not really needed if you're just brewing with the water. Brewing sterilizes everything.

 

[peterlonz]

Please don't take this the wrong way, just my two cents worth so to speak (ie High purity water treatment experience) but filtering alone will not remove bacteria from a water source, a 5 micron pre filter will remove sediment, the 0.5 micron carbon block will only remove taste and odors and any chlorine remaining, as there is always chlorine in town water. Sediment is not an indication that a water source is clean and healthy.
Even after filtering you will still have the potential of ecoli and coliforms in your tank water if its not being chlorinated to sanitize it.
do yourself a favor and have it tested if you dont believe me, ALS labs https://www.alsglobal.com/au?gclid=...4rCh3V2woMEAAYASAAEgKQ9fD_BwE#chooser-section
can do it for a reasonable price and peace of mind
once again just my 2 cents worth

What you say is essentially correct.
But I have not advocated brewing with only filtered tank water.
I filter only the good & very clean Gold Coast town water supply which of course has been chlorinated.
I can't speak with authority on what exactly a 0.5 micron filter can remove but I think Giardia is one removeable pathogen, E Coli I am uncertain but in a decent town supply you could regard this is irrelevelant.

 

[peterlonz]

A carbon filter is not really intended to 'filter'
To assure sterility, including a UV filter could add peace of mind. However, its not really needed if you're just brewing with the water. Brewing sterilizes everything.

My experience with UV sterilisation is not good. The UV elements seem to have an unduly short life & also their effectiveness is questionable. For example on our goldfish aquarium set-up we burn out one UV light every 6 months & it does not even impact on the algae.
I am NOT an expert on this subject, so others may have something to add.

 

[Lionman]

My experience with UV sterilisation is not good. The UV elements seem to have an unduly short life & also their effectiveness is questionable. For example on our goldfish aquarium set-up we burn out one UV light every 6 months & it does not even impact on the algae.
I am NOT an expert on this subject, so others may have something to add.

Given the UV light will be in an inline system with the pump, I'm not sure how it will limit algae growth in the tank? If you where pumping water from one tank with algae to another without algae then UV sterilisation will help prevent the algae from getting from one tank to the other. The only way it would kill algae in the tank is if you placed the lamp directly at the tank and the fish and observers of the tank probably wouldn't like that very much. They are rather dangerous.

It also needs to be the correct type of tube, there are a few types of UV lights, some will encourage algae growth. You need to use a germicidal lamp (UVC).

Best way to control algae is regular water changes, and get some algae eating fish.

 

[altone]

Given the UV light will be in an inline system with the pump, I'm not sure how it will limit algae growth in the tank? If you where pumping water from one tank with algae to another without algae then UV sterilisation will help prevent the algae from getting from one tank to the other. The only way it would kill algae in the tank is if you placed the lamp directly at the tank and the fish and observers of the tank probably wouldn't like that very much. They are rather dangerous.

It also needs to be the correct type of tube, there are a few types of UV lights, some will encourage algae growth. You need to use a germicidal lamp (UVC).

Best way to control algae is regular water changes, and get some algae eating fish.

Usually for aquariums the UV lamps are placed somewhere in an external filtration system.
If it's a purchased all in 1 filter, the UV lamps are usually way under powered for the flow going through them.
As for getting algae eating fish - goldfish - tick!
If it's an indoor aquarium to reduce the algae use the lights for a shorter time each day and reduce the amount you're overfeeding those fish

The on topic bit was the 2nd sentence btw.
Most inexpensive UV lamps get way more water flow than they can effectively clean.
And the real cheap ones do tend to not last very long.

 

[mischa6262]

Just out of interest, don't the UV water treatment units remove/neutralize e-coli etc?
I was under the impression they did.
Not an issue for me as I'm on town water - my issue is more removing Chlorine/Chloramine and if I can Flouride

After UV it will not remove ecoli or coliforms carcass's it will potentially kill it off but you need to filter it post UV with a sub 1um filter (ie 0.2um) FYI - when bacteria in water passes through a UV system it stresses the bacteria and it releases endotoxins as its defence barrier as it dies off this then needs to be filtered out.
but hey im on town water so i dont really care if people dont want to take my free advice

 

[mischa6262]

Given the UV light will be in an inline system with the pump, I'm not sure how it will limit algae growth in the tank? If you where pumping water from one tank with algae to another without algae then UV sterilisation will help prevent the algae from getting from one tank to the other. The only way it would kill algae in the tank is if you placed the lamp directly at the tank and the fish and observers of the tank probably wouldn't like that very much. They are rather dangerous.

It also needs to be the correct type of tube, there are a few types of UV lights, some will encourage algae growth. You need to use a germicidal lamp (UVC).

Best way to control algae is regular water changes, and get some algae eating fish.

UV will not stop algae growth, if running on tank water the intensity of the lamp will diminish rapidly within the first 3-6 months
And yes tank UV systems are normally for head space sanitation

 

[mischa6262]

My experience with UV sterilisation is not good. The UV elements seem to have an unduly short life & also their effectiveness is questionable. For example on our goldfish aquarium set-up we burn out one UV light every 6 months & it does not even impact on the algae.
I am NOT an expert on this subject, so others may have something to add.

FYI (not trying to teach you how to suck eggs, but some people don't know this) Treat a UV lamp and thimble (or sleeve) exactly like you would a quartz halogen headlight globe never never ever touch the lamp with your finger tips it will create a hotspot and cause the lamp to fail prematurely if you touch it clean it with isopropal alcohol and should be fine.

 

[Frothy Boi]

Sounds nice but it calculates at 1.8 L/min min flow to be effective, and are you filtering after uv? if not then you risk endotoxins still being in the water that are dangerous to humans we would filter post UV with a 0.2um absolute filter to remove endotoxins (coming from my exp in high purity water treatment systems)

1l/min is actually about my flow rate i get after running thru the filters, well below the required flow rate anyway. Filters then uv steriliser obviously. I will upgrade to a finer filter when they're due for replacement, still using the ones supplied. I'm also using flocculant and chlorine my tank if I have to fill from dam water which has been the case recently due to the lack of decent rainfall LOL i used to work for ALS actually.. but that's another story

 

[Clevohead]

We brew from rainwater tanks (recycled UBC 1,000ltr cubes) with no filters. I hear the whole bird poo argument all the time.

Look at your roof surface area vs the poo surface area on your roof, by the time the water makes the tank, there is bugger all poo in it to be honest, and to be honest with the way we keep our tanks clean I would rather drink our bird poo water vs what comes out of a town tap. I have seen what the inside of town water pipes and treatment plants look like on service jobs, hot tip: it ain't pretty.