rainwater harvesting system - gunge in attic storage tank blocking cistern fill valve

slipstream

Hiya,

I have a rainwater harvesting system which involves an underground rainwater tank and pump connected via a pressure switch/pump controller to a storage tank in the attic which in turn feeds our toilet cisterns. There is a coarse steel mesh on the pump and a leaf filter on the underground tank inlet to keep debris out. However, there are some leaves etc. in the tank at present as our builders left the cover off at times. This whole system was only installed a few months back as part of a major renovation.

We also have a geberit concealed cistern which has recently started to continually overflow into the bowl.

Pulling this apart, I found some black gunge in the water was preventing the fill valve from closing completely. Once cleaned, the problem recurred within a day.

When I look in the attic tank there is some (not a huge amount) floating and suspended stuff in there which I guess might be broken down organic matter or bacteria. There is also a slight smell when the water is disturbed. There is no light at the tank location but it is fairly (but not extremely) warm.

So, would you guys have any advise on simple ways I can filter out the gunk so it doesn't end up blocking fill valves? Are there simple filters/screens I could add to the tank inlet or outlet for instance?

Thanks for your advice!

air

You need to eliminate the organic matter getting into both tanks.
You will need to completely drain both tanks and clean them out and then install a proper filtration system between the incoming rainwater and the storage tank.

North West

Hi Slipstream
Are you feeding all water of roof to tank ? How many downpipes connected. Are there any filters on the downpipe. The filter you show is an external filter before the tank. You need to clean that regular. Is there a skimmer installed in the tank. The smell you get can be stopped by installing a carbon/odour 20" filter on the pipe before entering the tank. I am asking questions to find remedy for leaves etc.
NW

You may need to put in a first flush filter to catch debris

slipstream

North West wrote: »

Hi Slipstream
Are you feeding all water of roof to tank ? How many downpipes connected. Are there any filters on the downpipe. The filter you show is an external filter before the tank. You need to clean that regular. Is there a skimmer installed in the tank. The smell you get can be stopped by installing a carbon/odour 20" filter on the pipe before entering the tank. I am asking questions to find remedy for leaves etc.
NW

You may need to put in a first flush filter to catch debris

Hi NW,

We have two downpipes to gully grates which run underground to the tank. This filter is actually installed in the top of the tank in our case. We intended to have a skimming overflow siphon like this but could not fit one as our due to issues with levels/inverts to our overflow stormwater drain.

I don't think we have an ongoing problem with leaves as these are being filtered out by the downpipe grate, gullies and tank filter. However we do have a couple of handfuls of decomposed and decomposing leaves caused by the builder leaving the lid off.

I've put some tights on the storage tank inlet and the cistern fill valves have not blocked since. There is a slight smell from the water so I was thinking of killing off the organic matter with some chlorine or similar.

Slip

North West

Hi Slipstream
I have attached some info for you. This product can be bought from raincatchers,ie. Hope you find this information helpful.
NW