LFS says I need a large auto top off container - What?

[b7fig]

Currently I have a RODI hooked up to my sump with a float valve. LFS said to remove it from my sump and use auto top off in a container next to the sump because the float valve in a sump will never really shut off and continue making water.
I said okay, I'll run my RODI line to a 5 gal jug and put the float valve in it with a pump, to pump to the sump with a ATO.

He tells me i need at lease a 15 gal jug..... I said why, i only lose maybe a gallon or so a day and I have a 75 gal RODI unit. His only response, "trust me, you'll thank me later" What? Is there any reason why I need a 15+ gal ATO container instead of a 5 gal that would take up much less space?

[KafudaFish]

No.

Just fewer times of filling but it is good to check equipment regularly. There are many threads on here about equipment failures and not knowing for how long.

[Wazzel]

You do need to get a topoff container. Short cycling a RODI unit will shorten its life. I use a 10 gallon fish tank for my topoff container. I use about 5 gallons a week on my 60. It is nice to know I can go on a week long vacation and not worry about running out. IMO your container should be able to hold at least a weeks worth of topoff. You never know what life will throw at you, good to have some cushion.

[b7fig]

Well, I wouldn't even have to fill it. My RODI line runs to the container with a float valve. It would be auto filled.

[Wazzel]

Originally Posted by b7fig

Well, I wouldn't even have to fill it. My RODI line runs to the container with a float valve. It would be auto filled.

NO, that is not the proper way to operate an RODI unit. Short cycling will shorten the membrane life and not give you the best quality water.

[twon8]

Originally Posted by b7fig

Well, I wouldn't even have to fill it. My RODI line runs to the container with a float valve. It would be auto filled.

You should put a ball valve before the container and only open it when it is almost empty until it fills up then close it. Otherwise your rodi turns on everytime your ato runs which as said above will kill the life if your membrane.

[b7fig]

okay, that make sense. If I get a bigger container, I have longer to go if I forget to turn it back on before i run out of water

[d2mini]

Originally Posted by b7fig

okay, that make sense. If I get a bigger container, I have longer to go if I forget to turn it back on before i run out of water

Correct.
And if you have a controller, you can install a level sensor to let you know when it gets too low.

[smoothdog]

Also, if your float valve sticks open fresh water will run into your tank and flood it and drop SG until you find the problem and turn it off, then you will have flooded floors and dead stuff in your tank. Your top off tank should be big enough that you are not filling it constantly, but small enough that it won't flood your tank.

[d2mini]

Originally Posted by smoothdog

Also, if your float valve sticks open fresh water will run into your tank and flood it and drop SG until you find the problem and turn it off, then you will have flooded floors and dead stuff in your tank. Your top off tank should be big enough that you are not filling it constantly, but small enough that it won't flood your tank.

Except it's almost (notice I said almost) impossible for a regular float valve to stick open since they are buoyant and will be forced up as the water fills the container, turning it off. If they are going to stick, they will stick in the off position. That said, i have had an eshopps valve physically break on me, causing a constant drip. Luckily it was slow enough for me to realize something was wrong.

[smoothdog]

Originally Posted by d2mini

Except it's almost (notice I said almost) impossible for a regular float valve to stick open since they are buoyant and will be forced up as the water fills the container, turning it off. If they are going to stick, they will stick in the off position. That said, i have had an eshopps valve physically break on me, causing a constant drip. Luckily it was slow enough for me to realize something was wrong.

I should have said "fail" instead of "stick open". And yes, while these things are pretty reliable they are made of plastic and have been know to break from time to time. I've know people that replace them yearly to be safe since they are cheap to replace. I find that Mr. Murphy likes to step in whenever a single device is relied upon for critical things like this.

[d2mini]

Originally Posted by smoothdog

I should have said "fail" instead of "stick open". And yes, while these things are pretty reliable they are made of plastic and have been know to break from time to time. I've know people that replace them yearly to be safe since they are cheap to replace. I find that Mr. Murphy likes to step in whenever a single device is relied upon for critical things like this.

I think Mr Murphy has a special place in his heart for our hobby.

[reefgeezer]

Every time flow is started through an RO membrane, a small amount of waste water is passed through it. If you have a DI module, the contaminates in this small amount of waste water are removed before it can cause problems. If you allow your RO unit to cycle for short periods the expensive DI resin will be depleted very quickly... or if you don't have a DI module the contaminates will slowly build up in the tank.

The best way to run an RO unit is to allow it to run for a long time every time it is turned on. An ATO vessel is the best way to do this. Wait until the vessel is almost empty and then fill it up so the RO unit can run as long as possible. You could use a float switch to allow water to flow from the ATO vessel to the tank.

[Johnseye]

This will give you some great ideas about what you can do. The thread is titled sw mixing stations but there's good coverage for ato containers as well.

http://www.reefcentral.com/forums/sh...ixing+stations

I set up 2 tanks in my basement with tubing running to my sump. Peristaltic pumps (SpectraPure) do both ATO and auto changes from those tanks. I mix sw in one, and a kalk slurry in another and only have to re-fill the tanks about once a month.

This is the single most time and PITA saving investment I've made in my reef.

[b7fig]

Great information guys. Thanks for the info, apparently I've been doing it wrong for several years now! I better check my RO cartridges.

[ca1ore]

RODI lifespan aside, attaching an 'infinite FW reservoir' to your tank is a bad idea. In fact, I size my ATO reservoir on the assumption that at some point equipment failure will result in the full volume being added to my tank - when that happens I'd like to not have my sump overflow nor the SG fall to the point where stuff dies. I do go on vacation, however, so my reservoir also needs to be able to supply top off for 9 days. Let's round it up to 10. My tank loses about 1 1/2 gallons during dry weather (somewhat less during humid weather) so the ATO reservoir is 15 gallons.

[b7fig]

So I don't forget to turn the ball valve back on, could I not just plug my ATO pump into my apex controller and only have it run every 12 hours or every other day type thing. It still has the float switches to shut it off when the sump at correct water level.

[Bigcefa]

Yes adding a high and low switch plus the plastic float valve is how I'd do it.

[azjohnny]

I don't trust valves. I manually make my RO/DI. I fill a Brute 44 gal which takes me about 6hrs 2x a month, than I transfer about 20 gal a week into the ATO container

As is stated before run your RO/DI for as long as possible, fewer/larger runs is better than smaller/more frequent

[b7fig]

My issue is not with the float valves. I've used numerous of them for over 13 years and never had one cause an issue (yet). I'm just trying to not have my RODI unit turn off and on all day and/or have to manually remember to turn it on every couple of days. My thinking is to have my ATO plugged into my Apex and run a program that only turns in on say every other day. That way the RODI is not running constantly and I don't have to remember to turn the ball valve back on.

[azjohnny]

You could install an ASOV and connect to your RO/DI. I wouldn't want to make less than 30 gals at a time

What is your water pressure?

[Indymann99]

I use a 3.5g ATO reservoir and MANUALLY fill RODI via valve every other day. I have a float in the ATO res to let me know when its empty (and disable the ATO pump - via APeX).

Works great, and if I should have an ATO float valve "double failure" (I have 3 floats in the return section (LOW, ATO on/off, and HIGH) even if the entire 3.5g goes into the sump it wont overflow the sump.

I also run Kalk in the ATO and use an aqualifter pump.

Finally when I needed to go on a 10day vacation last spring I just linked 3x 5g buckets.

[Socalreef60]

Thats a pretty big variation of pump on pump off. For my 60 gallon set up my auto top off only tops off about 3/4" of water in my sump at a time. My concern would be that if your auto top off happens quickly with that much water you may shock some of your corals/fish when all that top off water mixes w the display tank :-/

[Indymann99]

pump ON and pump OFF is the RETURN PUMP.

when I do a WC, I turn OFF the RETURN pump... sump rises to PUMP OFF level. I pump out 20g from the sump, pump fresh SW back to the PUMP OFF level.
Restart RETURN pump. WC done in 7min no buckets.



The ATO runs ~ 8 times a day for 2-3 min each time.

[Socalreef60]

That makes sense, thanks for the clarification, thats a really good idea for water changes!