Hi all. I have drained one of my slimline rainwater tanks and there is about one inch of sediment in the bottom. How do I get it out? The sediment sits below the outlet port of the tank, so it will not drain out on its own. I also believe that I should not be pumping mud through a garden rainwater pump! Thanks.
cleaning rainwater tanks
(8 posts) (8 voices)-
Lance
Key MasterYou could use a wet vac, or you could fit the tank with a tankvac type overflow system that will continually remove the sludge. My small tank has the same prob, I will be making my own tankvac system when I get the time (assuming it ever rains here again).
Posted Tuesday 30 Jan 2018 @ 7:11:47 am from IP # -
David
MemberOnly an inch, typically the amount of "mud" that gets sucked through a garden water pump is pretty minute, would not worry about it, the axial pump can handle small amount of silt without any damage issues.
If you really need to get it clean, stand it on it's end wash the mud down and then tip the tank towards the filter basket hole, wash the bulk of the rest out with a hose, don't waste your time trying to get it perfect you'll waste a lot of water, trying to.
Posted Tuesday 30 Jan 2018 @ 8:15:33 pm from IP # -
scott drew
MemberThere are businesses that will do this for you, clean the sludge out. Not sure how they do it, syphon or vac, but I dont think they need to drain the tank to do so. They might use some of your water but not drain the lot.
I did one of mine a while ago. It is a 2500l tank and was less than 1/4 full. I got some 20mm tube, attached it to a long pole, got a syphon going and moved it around the bottom of the tank. It wasn't the easiest thing to do but worked ok.
You need to balance how much water gets syphoned out with enough suction to draw out the sludge. A garden hose may work but may be a bit small in diameter. Some sort of manifold, like a small vacuum nozzle will also increase the area you can clean in each run. Using a tube only just cleans the diameter of the tube. Using a long vacuum tube will use a lot of water as the vacuum tube is 40mm or so in diameter.
Posted Tuesday 30 Jan 2018 @ 8:55:57 pm from IP # -
Johnnojack
MemberAfter 6 years my 22kl tank had about 15mm of silt on the bottom. In winter while it was full I used a 25mm hose attached to a rigid pipe with a rubber fitting on the end. Siphon, no pump. Took about 3 hours as it is a big tank and lost about a quarter of the water. A more efficient vacuum type head would have been better. Harder to do when there is no water in the tank. Squirting water in to stir up mud and letting it drain out the tap will get some out but not all of it.
Posted Tuesday 30 Jan 2018 @ 10:08:52 pm from IP # -
Bushwalker
MemberWe added a floating intake inside the tank sits about 15cm below the water level. Will always have the best water unless the level drops to the bottom of the tank.
Posted Tuesday 30 Jan 2018 @ 11:01:10 pm from IP # -
Adamc73
MemberI’ve got a couple of meters of slotted 90 mm pipe that lays on the bottom of the tank connected to the overflow. When the tank is full and it overflows it’s sucking out all that sludge from the bottom without me having to do a thing. TAnkvac system looks like the same set up.
Posted Wednesday 31 Jan 2018 @ 9:54:18 am from IP # -
jdaley
MemberThe Tankvac system is gr8 and easily replicated, with no real loss of water since its the overflow.
Currently I shift water from one tank to another with a submersed pump and I let the first few seconds of discharge flow spill to the ground until in clears in colour. I loose about 10L at a timePosted Sunday 11 Feb 2018 @ 12:11:02 pm from IP #