Auto water change system- critiques

[PDAlber]

I've been thinking of adding an auto water change system to my tank, something simple and low-tech. Here's my plan:

First, the controller would disable the fresh water auto-topoff system for the duration of the water change cycle. Next, my controller starts a Tom's Aqualifter to pump salt water out of the "return" section of the sump. The pickup for the pump would be fixed just below the water level, as a fail safe, to prevent too much water from being pumped out. After the Aqualifter times out, new salt water is pumped from the reservoir into the return section until the normal water level is restored. The pump for the new salt water would be controlled by a dedicated float switch in the sump, and run on a timer (as a fail safe). A low-water float switch in the reservoir would prevent the cycle from running if the reservoir is empty. After the cycle is complete, the fresh water auto topoff resumes.

My plan is for 2-3 cycles per day, changing a total of 1-2 gallons per day in my 90 gallon tank.

Any thoughts? Any problems that need to be addressed?

 

[Siptang]

That actually sounds interesting and will work. I think Matt (mrx) has set up his tank like that in the past but he has now changed to bigger changes. To me honestly, I prefer bigger changes at once and tom's aqua lifter is bit too small and too slow to do an water change.

 

[ReefKeeper64]

That's actually a smart design. Only thing is I would go with a used tunze osmolator over the new aqualifter. They are accurate and dependable.

 

[PDAlber]

I would still do occasional large volume water changes to remove waste from the display tank.

 

[mrx66699]

bypass all the controller stuff and float switch stuff and just use a Masterflex Dual Headed Peristaltic pump....I have one and it will take exact amounts out and return same exact amounts at the same time .....its more exact than any aqua controller or aqualifter pump or tunze.....its what they use for kidney dialysis .....its essentially a continuous water change setup

 

[PDAlber]

They're pretty sweet, but pricey.

 

[tommy tomato]

I like it. The only thing is you will need to have your SW res very close to the sump because an aqua lifter won't pump very far. Running a dual tunze system would be sweet but expensive. How about a couple of maxi jets instead of the aqua lifters?

Also where is the waste water going? A aqua lifter is going to pump it to a container right next to your sump and that's about it, unless your running a drain down hill. Then Your back to emptying buckets. Kinda defeats the purpose of automation. I have my waste water piped to my washing machine drain so I need a pump with a little power to get it over there. I'm digging your design tho. It takes me 26 seconds to do a 5 gallon waterchange right now but this is even easier lol

 

[METZCOOL]

Been using a Litermeter 3 for auto water changes for years, change 2% of total water volume daily and the pumps are calibrated and my salinity has never waivered. They are sold by Spectrapure and they have excellent tech support. Have heard the argument of larger water changes are better but I have 90% sps tank and have been doing it this way for over 6 years and orp levels stay in the low 400 range without any issues.

 

[marke]

Bypass the float switch and waste seawater pump. Drill a hole in the sump at the high water mark install bulk head and run PVC or tubing to your drain. So long as the drain is below the high watermark it will run out by gravity as you add seawater to your display without turning your system off. No need to mess with the ro top off either as the high water exit should be higher than the ro in spot Hope this makes sense but if you ask I can clarify

 

[PDAlber]

Actually, that makes perfect sense. However, if the power goes out, I will lose water as it drains into the sump. I don't have a battery backup.

 

[PDAlber]

I like it. The only thing is you will need to have your SW res very close to the sump because an aqua lifter won't pump very far. Running a dual tunze system would be sweet but expensive. How about a couple of maxi jets instead of the aqua lifters?

Also where is the waste water going? A aqua lifter is going to pump it to a container right next to your sump and that's about it, unless your running a drain down hill. Then Your back to emptying buckets. Kinda defeats the purpose of automation. I have my waste water piped to my washing machine drain so I need a pump with a little power to get it over there. I'm digging your design tho. It takes me 26 seconds to do a 5 gallon waterchange right now but this is even easier lol

The waste water would go through the wall and drain on the ground under my deck. I don't have a drain nearby.

 

[tommy tomato]

The waste water would go through the wall and drain on the ground under my deck. I don't have a drain nearby.

Ok that works!

 

[ReefKeeper64]

Actually, that makes perfect sense. However, if the power goes out, I will lose water as it drains into the sump. I don't have a battery backup.

Yeah, I was thinking about that scenario too. Plus, if I just have the pump off for maintenance I'd have the same issue. Is there a workaround?

 

[Stylo328]

Actually, that makes perfect sense. However, if the power goes out, I will lose water as it drains into the sump. I don't have a battery backup.

Ball-valve the bulkhead for the high drain. Instead of a small daily change, use the system on fixed days and times (when you are available) and open the valve only during that period. Just a thought.

 

[Johnic]

bypass all the controller stuff and float switch stuff and just use a Masterflex Dual Headed Peristaltic pump....I have one and it will take exact amounts out and return same exact amounts at the same time .....its more exact than any aqua controller or aqualifter pump or tunze.....its what they use for kidney dialysis .....its essentially a continuous water change setup

Question: does this run all day just swapping out water and adding new water or does this pump have a timer?

 

[Rogger Castells]

What ever you do make sure that the new water container is below the sump level (not as in picture) otherwise once the pump stops the water will continue to flow by gravity

 

[doreo]

i like this idea but it seems way to complicated. To many points of failure. i like the gravity driven ones ive seen that just use gravity and a valve with pumps to return water. But i do like the idea of this set up. i can always thumbs up complicated and flashy

 

[Kayo2289]

All this seems excellent but something about automizing water changes scares me...

I would say just keep it as simple as possible while still using the reservoir but cutting out the controller and gravity feeding the New SW... but hey thats just me and I know that wasn't the point of this post...

After you complete your setup a quick little video showing its functionality would be nice.

 

[ReefKeeper64]

bypass all the controller stuff and float switch stuff and just use a Masterflex Dual Headed Peristaltic pump....I have one and it will take exact amounts out and return same exact amounts at the same time .....its more exact than any aqua controller or aqualifter pump or tunze.....its what they use for kidney dialysis .....its essentially a continuous water change setup

I too have a masterflex for a steady water change but I still require a separate ATO to address evaporation.

 

[ReefKeeper64]

Question: does this run all day just swapping out water and adding new water or does this pump have a timer?

My masterflex runs on a timer set to run for 15 minutes in the morning and another 15 minutes in the evening. The timer is set to run this way daily and this simple system changes out about a gallon of water per day this way. By adjusting the speed at which it runs or the amount of time it runs, I could dial it back to change as little as a cup of water a day or as much as 25 gallons of water a day (probably more).

Its easy to manage water changes with these pumps. I made the investment in one ($150 used) when I bought a Lynkia starfish about a year ago and I'm glad I did because salinity has stayed steady ever since and the Lynkia is thriving to this day. (Lynkias are extremely sensitive to changes in salinity)