Automated water changes

[Liam]

I am thinking of setting up an automated water change system where 2 pumps one of which will be in the sump and the other in my make up resevoir.The pumps will be controlled by the same time and will come on for a set amount of time each day to do a small water change.
I am looking for ideas on what pumps to use,i need about 4 foot head and 8 feet horizontal.I want to use the smallest pumps possible to give a nice slow water change of about 3 gallons.
Any thoughts welcome.
thanks,Liam.

 

[objectfire]

Someone makes a pump that has two inlets / outlets to guarantee the same rate both ways. Costs a few dollars, though.

 

[Liam]

Someone makes a pump that has two inlets / outlets to guarantee the same rate both ways. Costs a few dollars, though.

Does it draw from a different resevoir,while pumping from the sump?

 

[NateHanson]

You can get peristaltic pumps with a head that pumps two tubes simultaneously. That would work I would think. They aren't very fast though.

 

[Liam]

You can get peristaltic pumps with a head that pumps two tubes simultaneously. That would work I would think. They aren't very fast though.

I think they might be too slow,i want to get the water out a little faster so that there is little chance of removing recirculated new water.I am thinking maybe two 500 gph pumps,i can then adjust the flow to give the exact same removal rate even with different heads and distances.

 

[Scuba_Dave]

I think the problem with a lot of automated systems is the chance of failure increases. If the outgoing pump sticks open then you could drain your tank/sump. If it sticks & doesn't open, possible flood.

Same problems with the other pump. I "automated" my water changes as much as I want to. I use my recirc pump & open a valve which pumps the "bad" water down a drain. I then use another pump to pump new SW into the sump

 

[Member No. 1]

Sorry for being stupid, but why would you want to automate this?

I would think you could use the water change to siphon any detritus from the bottom of your tank or sump.
How much do you change a week? How big is the tank? Some things are great working by themselves, but I can see a lot of problems creeping up. Just no way to get both pumps to flow the same. As your make up tank gets lower from filling your main tank, the head pressure will increase and the flow will change.
This is just one problem that might happen.

 

[Liam]

Sorry for being stupid, but why would you want to automate this?

I would think you could use the water change to siphon any detritus from the bottom of your tank or sump.
How much do you change a week? How big is the tank? Some things are great working by themselves, but I can see a lot of problems creeping up. Just no way to get both pumps to flow the same. As your make up tank gets lower from filling your main tank, the head pressure will increase and the flow will change.
This is just one problem that might happen.

I want to automate to reduce maintenance,my system will be around 170 gallons,so weekly water changes are large .There are many benifits to small daily water changes,especially system health.I am only talking 3-4 gallons a day.Both pumps will be controlled simultaniously by the same digital timer.I have never heard of one of these sticking.Should the draining pump fail my system can easily absorb the 3-4 gallons without a problem.

 

[Corwyn]

this may work for you at 3.5 gph I think it's more than enough for a 170G.
The upside is they are cheap. Downside is I don't know how reliable they are
at that price.
I am ordering one to use for top off. I will set the timer to come on for about 10 minutes every 3 hours and adjust as I need for evap.

http://www.marinedepot.com/md_viewItem.asp?idproduct=KTALP&ast=&key=
Corwy

 

[Member No. 1]

another option

I take it this is a basement set up. If so then you only need one pump. Put an overflow tube or a bulkhead fitting in your sump at the maximun water level you want. Plumb back to basement drain. Then you can fill with make up water and any excess with be removed via the drain. Plus if you pump sticks on, worst case is you dump all of your replacement water down the drain, but it will not overflow your tank or sump. Follow me?

 

[Liam]

I take it this is a basement set up. If so then you only need one pump. Put an overflow tube or a bulkhead fitting in your sump at the maximun water level you want. Plumb back to basement drain. Then you can fill with make up water and any excess with be removed via the drain. Plus if you pump sticks on, worst case is you dump all of your replacement water down the drain, but it will not overflow your tank or sump. Follow me?

What if there is a power outage

 

[NateHanson]

My thought exactly.

 

[Member No. 1]

Nothing!
The bulkhead fitting/standpipe is the MAX level you want. Not a return loop to the basement. No water would be going down this pipe normally. When your auto-changer kicks in, your sump fills to the MAX level, and the excess THEN runs to the basement to the drain. So if the power goes off, the auto-change pump isn't running. You could set up a minimum float switch so if you do get a power outage, and your main tank does drain higher than the overflow pipe, then when power comes back on, it would refill to the proper level.
Follow me?

 

[NateHanson]

Nothing!
The bulkhead fitting/standpipe is the MAX level you want. Not a return loop to the basement. No water would be going down this pipe normally. When your auto-changer kicks in, your sump fills to the MAX level, and the excess THEN runs to the basement to the drain. So if the power goes off, the auto-change pump isn't running. You could set up a minimum float switch so if you do get a power outage, and your main tank does drain higher than the overflow pipe, then when power comes back on, it would refill to the proper level.
Follow me?

In a power outage the return pump will stop running. So as the plumbing and display tank drain down into the sump the water level goes up a few inches. All that extra gallonage from the display tank and plumbing will now overflow through your U-tube siphon, out of the sump, into the small bucket intended to hold the water-change water, and presumably onto Liam's nice new floor.

 

[Member No. 1]

But, I think no matter what system you decide to use, you will have to have some sort of float arrangement, and with this, you will have to monitor your salinity closely.
In the long run, might be easier to do them by hand.

 

[skyedolphan]

just be careful that the damn tube ussed doesnt somehow fall into the sumpcause you ae looking at a big syphon of ro into your display trust me

 

[Member No. 1]

In a power outage the return pump will stop running. So as the plumbing and display tank drain down into the sump the water level goes up a few inches. All that extra gallonage from the display tank and plumbing will now overflow through your U-tube siphon, out of the sump, into the small bucket intended to hold the water-change water, and presumably onto Liam's nice new floor.

This in not a siphon device. It's more like a stand pipe or a bulkhead fitting up higher than the regular water line in the sump.
That is way I asked if this was in the basement. If so,he would have to run two lines anyway. A fill line ( pump in basement with new SW) a return line ( pump in the sump) to pump out the "dirty" water. This would all be hard plumbed.

 

[NateHanson]

Ok then, put a bulkhead fitting in the side of the sump, with the normal sump level right below that bulkhead. Is that what you're saying? So when the water change pump turns on and pumps new water into the system an equivalent volume will flow out of the sump through the bulkhead fitting? Am I understanding correctly?

What happens when there's a power outage and the sump fills up with water that empties out of the plumbing and top inch of the display tank? Won't all that gallonage go out your bulkhead where the water change water is supposed to go out? And then when the pump goes back on, auto-top-off will dillute the salinity of the water, to get it back up to the normal spot below the bulkhead.

Maybe I'm still misunderstanding you?

 

[Liam]

I think i have come with a solution to prevent siphoning(which would be a problem beause my sump is lower than the level of my resevior).My idea is to pump the make up water through appropriately sized pipe until i reach the end of the horizontal run above the sump,i then plan to make the drop to the sump with a much larger diameter pipe and have the horizontal feed connect into the side of the vertical pipe with a barb connector.I would leave the top of the pipe open to atmosphere,this should prevent any chance of starting a siphon.
I hope anyway

 

[Member No. 1]

I think you got it. But it's not a "top off" it's an auto changer. SW for SW