Automatic water changes on 25 gallon

[sammer]

I am considering seting up and automatic water change system for a 25 gallon tank with sump.

Would this be a really bad idea for a small system?
I would use my apex controller with float switches and temp monitors etc for the NSW bucket.

I would also use just two small pumps for adding and removing water (about 1 gallon per min)

Any thoughts

Thanks

[Cal_stir]

How will you monitor your NSW so you don't accidentally do a WC if the salinity isn't correct or the NSW tank is empty?

[NanoCat]

If I were to do this:
I would use a float switch in the nsw to stop the process if there is not enough water and possibly use a salinity probe to check the salinity or just manually check it with my refractometer every few days. The mix up water I use now barely evaporates (no salinity shift) covered 5 gallon bucket over a weeks time anyways so as long as the batch it the correct salinity it should be ok.

I would also use a temp probe and a heater to match exactly the dt temp.

[sammer]

This is essentially what I would do Nanocat.

Does anyone see any problems with this or have suggestions. I would plan on changing about a 1/2 gallon or so every day.

[fishytime]

methinks it would be a mighty fine balancing act.....trying to match flow rates of two different pumps will be tricky and I would suspect that you will be constantly adjusting and tweeking the times as the pump/hoses get dirty.....and then there is the "what ifs".....what if one of the pumps fail or doesnt start properly?....might be a flood or a return pump running dry waiting to happen.....that and mechanical float valves have been known to fail

[Reefie]

+1
Keep in mind that the pump that pumps water OUT will be more efficient due to gravity helping than the pump that pumps water UP and IN.

I had thought of doing something like this with my BC29, until I researched that. Too many variables to factor in to make it worthwhile.

Originally Posted by fishytime

methinks it would be a mighty fine balancing act.....trying to match flow rates of two different pumps will be tricky and I would suspect that you will be constantly adjusting and tweeking the times as the pump/hoses get dirty.....and then there is the "what ifs".....what if one of the pumps fail or doesnt start properly?....might be a flood or a return pump running dry waiting to happen.....that and mechanical float valves have been known to fail

[lapdog2020]

I had on my 30 g tank and worked like a charm. But sorry to say it was not a automatic changer. There was some manual duties that came with mine. To drain the change tank I had to run it to my drain with a ball valve. Since I hade to drains in my tank. The set up was drain 1 went to my sump and the 2 drain went to my change tank and my change tank went to my sump. Drain 2 had a ball valve that I could close so I could do a water change.

[mike31154]

By design any automatic water change set up will involve quite a few components and be relatively complex with controllers, pumps, timers, switches, relays etc. All this complexity means more failure modes, more things to potentially go wrong. Makes no sense to me to spend the money on such complexity for a simple task like a water change on a small tank. In the end, you still have to mix the new salt water manually, so how much more time does it take to scoop some water out of your display or sump & replace it manually? I have seen threads on other forums where individuals are working on methods of mixing up new salt water automatically, but they usually end somewhere along the line when the poster realizes just how hard it is to get a consistent mix using machinery. Even on a larger system I would be hesitant to let an auto water change system run unsupervised. I would look at it more as a labour saving device to minimize the manual water hauling by using pumps to transfer water on larger systems, but would still control the pumps manually for peace of mind. But that's just me & yes, I still haul buckets of new salt water from the basement up to my display for water changes. For me it's part of the deal of owning a SW tank & I don't mind too much since I'm on a less frequent, larger volume water change schedule.

[burgerchow]

Originally Posted by mike31154

By design any automatic water change set up will involve quite a few components and be relatively complex with controllers, pumps, timers, switches, relays etc. All this complexity means more failure modes, more things to potentially go wrong. Makes no sense to me to spend the money on such complexity for a simple task like a water change on a small tank. In the end, you still have to mix the new salt water manually, so how much more time does it take to scoop some water out of your display or sump & replace it manually? I have seen threads on other forums where individuals are working on methods of mixing up new salt water automatically, but they usually end somewhere along the line when the poster realizes just how hard it is to get a consistent mix using machinery. Even on a larger system I would be hesitant to let an auto water change system run unsupervised. I would look at it more as a labour saving device to minimize the manual water hauling by using pumps to transfer water on larger systems, but would still control the pumps manually for peace of mind. But that's just me & yes, I still haul buckets of new salt water from the basement up to my display for water changes. For me it's part of the deal of owning a SW tank & I don't mind too much since I'm on a less frequent, larger volume water change schedule.

Totally agree. I still lug up 25 gallons of water from basement to main floor every water change. Less plumbing = less chance of disaster

[Reefie]

Originally Posted by burgerchow

Totally agree. I still lug up 25 gallons of water from basement to main floor every water change. Less plumbing = less chance of disaster

I used to do that how ever I was only doing about 10-15 gallons per WC. Being my usual self of trying to find ways to be more efficient, I picked up a Mag3 pump and 50 ft of 3/4" tubing, an MJ-1200 and another 10 ft of 1/2" tubing. The RO/DI & SW mixing containers are 50 ft away from my tank, so I now use the Mag3 to pump in fresh SW and the MJ-1200 to pump out dirty SW from my tank. WC's now only take me 20 mins.