Water change automation

[jameson_uk]

I don't have the time to go as far as @ian_m with his amazing water change setup

Having moved from buckets to a Python I can't go back but the variation in temperature from my combi boiler is getting a bit frustrating (means I keep having to check the temperature of water going into the tank and often have several trips back to the sink in an attempt to find a magical combination of cold and hot that is somewhere near the tank temperature)

Got me thinking that refilling could be a lot simpler by just using a tub (water butt?) and a pump and live with the time it would take an aquarium heater to get the water close to the tank temperature. Would I need to get a specific water container or would a cheap water butt work?

Also came across http://www.wickes.co.uk/Wickes-Water-Butt-Pump/p/194554 which is in stock locally and for £20 a lot cheaper than most powerful submersible pumps and includes a low level cut off too. Max flow is 2,400 lph which I guess would uproot most things but it says it is adjustable and perhaps I could create some sort of spray bar type setup to spread the output over the whole tank?

This would then just leave getting water out. Using a submersible pump would work but I ideally want to syphon some of the substrate not just remove water. Other than just using the Python I have is there a better way of doing this?

Also out of interest is there any benefit in leaving the water? With some surface agitation there should be some gassing off but does this actually make any difference to just filling up straight from the tap?

Any thoughts?

 

[Al Grant]

In my 200l tank I use a small 12v submersible water pump that has a gentle 7L per/min flow through a 13mm hose
I need the pump to be small and fit into my 25L water change jerry cans and it will empty one in around 3 mins with no disturbance in the tank (however I have added a DIY diffuser to stop the flow going towards the substrate).
Using this I can fill 75ltr in under 10 mins with minimum mess and no disturbed substrate, plants or fish.

Due to the position of my tank, I find lining 3 or 4 jerry cans up next to the tank to be easier than running hoses through the house.

If you're using a bigger water container then this company have a number of options http://www.rainbow-conversions.co.uk/water-pumps/page/1/
The smaller ones seem to be rated anywhere between 7 - 15 L/per min. They are meant for caravans so all seem to be 12v so a 240v adapter would be needed (extra cost).

 

[ian_m]

Glad you like my solution of water butt heater.

live with the time it would take an aquarium heater to get the water close to the tank temperature

With a 200W aquarium heater and 100litres of water raising 10'C you will be looking at....

Specific heat capacity of water is 4200J/'C/Kg, heater is 200W which is 200J/s.

Thus time to raise 1Kg of water 1'C is 4200/200 -> 21seconds.

For 100Kg of water raising it 10'C time is 21 x 100 X 10 -> 21,000s -> 6 hours !!!! This is not taking into account losses which may increase time by 50%. Or use 3000W like I did, and it takes only 20minutes, according to calculations (I typically find it take about 12 minutes to heat my 90 litres to 24'C).

So using an aquarium heater is an over night job. Just make sure the heater doesn't touch the butts side or else it will melt a hole and you end up with a wet floor and burnt out heater, been done on this forum quite a few times.

During research I did find quite a few people who just used a hose to fill a water butt (in garage), add dechlorinator and dangle a 300W aquarium heater in it the night before they needed the water. Then use a small submersible pump to pump it into their tank the next day.

Also came across http://www.wickes.co.uk/Wickes-Water-Butt-Pump/p/194554 which is in stock locally and for £20 a lot cheaper

This is way way too powerful, you will have hoses blowing off and monsterous amount of water getting everywhere except in the tank. This is meant for watering the garden. I use a 1000l/hr submersible pump, fine and controllable and doesn't wash the tank substrate away.

This would then just leave getting water out

Can you syphon from tank out a windows onto a lawn ? I syphon into a large yellow bucket, before pumping onto front lawn. Handy thing about this you can catch things eg plants, fish etc that shouldn't have been syphoned out before they end up on the lawn.

One person I found, drilled a hole in the wall near his tank, fitted some pipe with hose attachment on the end, that went outside to a large sprinkler bar attached to the wall of the house. At water change time he just connected a hose and syphoned/pumped water from tank to sprinkler bar that watered his lawn and plants.

Also out of interest is there any benefit in leaving the water?

Yes if water is chlorinated the chlorine will dissipate after 24 hours, even quicker if agitated with an air stone. However if chloramine has been used, then aeration has little effect. So always always always add dechlorinator.

 

[Zeus.]

I was lucky as tap is water Ok and no water softers like Ian. Just reused old shower mixer and hose.

With 500l tank it cuts WC time down esp when water at nearly 3bar. Get free electric and gas on sundays 9am till 5pm so try and fit it in then.

 

[ian_m]

Taking it one further....

Saw someone who was using a Dafi under sink water heater. See Ebay etc for Dafi heaters. Use 3.7kW version so you/electrician can wire it directly to ring main. Output of this was connected to a blending valve set to 24'C, thus he got continuous 24'C water to his tank.