Auto Water Change ideas???

[sphelps]

If you want to keep a premixed salt storage tank then there is another fairly simple system you can employ.

• You essentially have two top off systems, one for fresh water and one for salt water.
• The fresh water top off works with a slow fill principal (slow pump or restricted solenoid valve).
• Saltwater top off works with a fast fill principal (large pump from storage container).
• Float switch for fresh water top off is located at standard height to maintain standard water level in sump. Should be controlled so water level remains fairly constant 24/7.
• Float switch for saltwater top off is located slightly below the float for fresh water.
• A pump on a timer pumps water out of the sump to a drain on a certain schedule to remove the desired amount of water.

Now the idea is the fresh water top off maintains the water level in the sump so the saltwater float isn't triggered from evaporation. However when the drain pump is activated the fresh water top off will be too slow to keep up so the salt flow will trigger and since it's fast fill, will top the tank back up before much fresh water is added. You'll also want to maintain the salinity of the storage tank slightly higher than the desired aquarium sanity as some extra fresh water will obviously be added every time saltwater is added.

[BC564]

Im using a PLC , solenoids, and a pressure transmitter in inches of water column (4-20 ma)....premixed salt water tank, RO tank for top off, 3 RTD inputs for temperatures (of all 3 tanks), pH probe input, etc..... I always use the same salt and know the amount of salt needed to make 25 litres of salt water, but I'm pretty sure I can be there for the actually test of the SG.

[wolf_bluejay]

What I have at the moment is a 30 gal tank for mixing saltwater, and a feed off my pump that runs to my basement drain. The mixing tank has a power head that has a "closed loop" and a feed to the sump. To do a water change, I just open the valve to the drain and pump out 20-30 gal, close that valve, open the one from the mixing tank and pump in until I'm back up to the proper level.

What I was thinking about doing is this: drill the sump just a smidge about the normal water level (and ATO float switch level) and pump in a bulkhead straight to a drain. Then putting the pump from the mixing tank on a timer to run for a few minutes each day. The water level would rise in the sump and almost the same amount of water I pump in would overflow into the drain. This would allow for my existing ATO to work as normal and the only thing I would have to do it manually refill,and salt and mix the mixing tank. The water changes would happen a few gallons at a time each day.

This risk is that during a power outage or some other event that changes the sump level, the excess water would flow out the drain an be replaced by fresh water when the power returns. But I've only had 1 power outage in 2 years and the fresh water is topped up real slow. So, I'd only loose a few gallons of water on about 250 gal total system volume.

[BC564]

That would work....I would just keep an eye on your SG....

[untamed]

Originally Posted by sphelps

If you want to keep a premixed salt storage tank then there is another fairly simple system you can employ.

• You essentially have two top off systems, one for fresh water and one for salt water.
• The fresh water top off works with a slow fill principal (slow pump or restricted solenoid valve).
• Saltwater top off works with a fast fill principal (large pump from storage container).
• Float switch for fresh water top off is located at standard height to maintain standard water level in sump. Should be controlled so water level remains fairly constant 24/7.
• Float switch for saltwater top off is located slightly below the float for fresh water.
• A pump on a timer pumps water out of the sump to a drain on a certain schedule to remove the desired amount of water.

Now the idea is the fresh water top off maintains the water level in the sump so the saltwater float isn't triggered from evaporation. However when the drain pump is activated the fresh water top off will be too slow to keep up so the salt flow will trigger and since it's fast fill, will top the tank back up before much fresh water is added. You'll also want to maintain the salinity of the storage tank slightly higher than the desired aquarium sanity as some extra fresh water will obviously be added every time saltwater is added.

I think that is pretty clever. You could add an additional, lower level, level sensor and only allow the fast SW fill cycle to initiate if BOTH the upper level AND lower level sensors are low. The only time that the lower level sensor would be low was during the extreme of a water change dump.

This gets around the problem of having the fast-fill trigger every time the sump even goes just a little bit low. It would wait until the sump is dramatically low.

An aquarium controller could handle that kind of logic. I know that Aquatronica could do it, and I assume that Profilux could also handle that.

In fact, while I've not rigged it to run automatically...what you describe is exactly what happens in my system during a water change. Even as I am refilling the WC sump with new SW, RO water is leaking slowing in because the main sump level is low. This extra top off water is insignificant in my system. In fact, because this is "extra" water added, the system returns to normal as this water evaporates away later. (that only works that way because I have 2 sumps)

[banditpowdercoat]

Originally Posted by sphelps

So do a water change every three weeks. I have a system setup on my tank similar to what I described earlier but I have to manually activate the pump, this way I can do it whenever I'm available. Takes about 2 minutes to change 10 gallons and I don't have to have premixed water ready prior to this. Best of all the hole system is just a pump on a switch and bucket of salt with a cup

So, you add 10g of fresh water to tank, THEN add salt? Isn't this bad? Takes a while for the salt to mix thoroughly, doesn't it?

You've followed a couple of my other posts, you know I like making things complicated LOL Now, if I could rig something to dispense pre measured amounts of salt daily, then I could do a .5g daily auto change and add salt directly to the Sump. Key is getting the salt dispenser to work right.

I know nothing is failsafe, and This is not to get me ouyt of doing the tank checks. I am a Maintenance Electrician, Know all about PM checks and things failing and such. I would really like to be able to make sure the tanks water is god when I am away at camp for 3 weeks at a time. The Mrs isnt allways on top of things.

Sure, I could make up 25g of premix, and set up a drain/fill with that, BUT, I am also trying to get RID of the 2 rubbermaid cans in the dining room, not add more. If a effective ATO flush/fill and Water change setup could be devised, I should theoretically be able to get away with 5g or less RO storage

[banditpowdercoat]

Originally Posted by sphelps

If you want to keep a premixed salt storage tank then there is another fairly simple system you can employ.

• You essentially have two top off systems, one for fresh water and one for salt water.
• The fresh water top off works with a slow fill principal (slow pump or restricted solenoid valve).
• Saltwater top off works with a fast fill principal (large pump from storage container).
• Float switch for fresh water top off is located at standard height to maintain standard water level in sump. Should be controlled so water level remains fairly constant 24/7.
• Float switch for saltwater top off is located slightly below the float for fresh water.
• A pump on a timer pumps water out of the sump to a drain on a certain schedule to remove the desired amount of water.

Now the idea is the fresh water top off maintains the water level in the sump so the saltwater float isn't triggered from evaporation. However when the drain pump is activated the fresh water top off will be too slow to keep up so the salt flow will trigger and since it's fast fill, will top the tank back up before much fresh water is added. You'll also want to maintain the salinity of the storage tank slightly higher than the desired aquarium sanity as some extra fresh water will obviously be added every time saltwater is added.

If you use 2 separate float controls, and set the upper limit for both the SW fill and the FW top off at the same level, then you would not need to up the Sg in the fill water. That is how I was planning to run my setup. ATO and SW use separate start floats, but the same stop float so that no salinity is lost in the tank. Thats the easy part. Its making the SW automatically thats the tricky part. So I dont have to store 50g of SW for changes when I'm away.

PS, If I get this right, I have a feeling those of you with LARGE tanks would love it. 400g+, must get tiresome mixing all the SW up all the time, huh?

[sphelps]

Originally Posted by banditpowdercoat

So, you add 10g of fresh water to tank, THEN add salt? Isn't this bad? Takes a while for the salt to mix thoroughly, doesn't it?

I don't think it has any negative effects. I add the salt to specific chamber which contains a filter floss material which holds the salt and as the return flow passes through it dissolves the salt. Doing this I don't even get a white build up in the sump like you might expect, it is however RB salt which might be better for this. I've also been doing this for years in mine and other clients tanks with no signs of any negative effects. Note that I do this with a ~180 gallon system changing 10 gallons weekly.

I know some people like to complicate things and I use to be the same but my experience in the hobby and general every day engineering has taught me that simpler is always better. And although nothing is 100% fail safe it's pretty easy to make something 99.9% fail safe if you keep it simple.

Manually adding the salt will eliminate the need for the extra Rubbermaids, you can buy a larger RO storage tank that can be placed anywhere that you can run a single line from your RO unit. You don't have to make do with the standard 4 or 5 gallon tank.

[golf nut]

Originally Posted by sphelps

. Note that I do this with a ~180 gallon system changing 10 gallons weekly.

How much water would you need to completely dissolve the amount salt you need for 10 gallons, and how long would you think it would stay completely dissolved?.

I designed a mixing device years ago for fuel additives that automatically dosed the correct percentage of additive to each gallon of fuel, this may work well in this application.

[sphelps]

Originally Posted by banditpowdercoat

If you use 2 separate float controls, and set the upper limit for both the SW fill and the FW top off at the same level, then you would not need to up the Sg in the fill water. That is how I was planning to run my setup. ATO and SW use separate start floats, but the same stop float so that no salinity is lost in the tank. Thats the easy part. Its making the SW automatically thats the tricky part. So I dont have to store 50g of SW for changes when I'm away.

PS, If I get this right, I have a feeling those of you with LARGE tanks would love it. 400g+, must get tiresome mixing all the SW up all the time, huh?

Yeah that works if you run that style of top off, I however don't usually use such systems. The systems I use only have one float switch for level control and some have an extra float switch up higher but only for safety if the primary were to fail. Either way same thing.

I also agree with the rest, I also don't consider a system automated unless you do absolutely nothing but I've been down that road and invested money into R&D trying to develop a way of adding salt automatically. In the end I concluded that there wasn't an efficient way to do it, anything that would work reliably was too expensive and still not that reliable. Biggest problem is humidity, even in low humid environments salt will clump up quickly if exposed and combined with the typically more humid environments, where open water exists, this problem is amplified. This makes it even more difficult to implement.

Like I said before in the end adding a few cups of salt on a regular bases is a very simple task, unless you married a turkey I think she could probably manage. You could even set an alarm to remind her

Please note I meant absolutely no offense with any of this, just had to say it, I've noticed an increase in sensitivity over the last few months