Auto-Top-Off Solutions

[alrha]

Large tanks and small tanks alike have the need to "Top-Off."

As water naturally evaporates from our tanks, we need to replace that evaporated water with fresh water.

Rather than just pouring in fresh water in the tank whenever one feels like it (and resulting in fluctuating salinity as the water gets more/less salty as the water evaporates/replenishes) there are various options to have this process automated.

Typically, fresh water will be stored in a reservior (bucket) near the tank (or in the stand). This water can be systematically added to the reef.

Note: Some people use their RO/DI storage as the reservoir. This is risky as there is always the risk that some failure of the Auto-Top-Off may result in too much fresh water being added to the tank resulting in diluting the salinity of the tank too much, or a flood, or both.

To avoid this risk, many choose to just use a small reservior that is refilled every couple of days so that the amount of fresh water added to the tank, in the event of a failure of the Top-Off, is limited.

Some options to Automate the Top-Off include:
1) Float Valve - this will be open when the water level decreases (due to evaporation) allowing fresh water into the sump/tank, and when the water level rises, the valve will float and close.
2) Float Switch - this will activate a pump (that is plugged into the float switch) when the water level is low, and will shut power to the pump when the water level rises. The pump will be in the reservior to pump the water into the sump/tank.
3) Dosing Pump - this will add the water to the sump/tank at a set rate (which the user can program to be close to the evaporation rate). This would be the most uniform addition of freshwater as it would be at a constant rate (compared to the on/off of the float switch/valve), but would not be guaranteed to be at the same exact rate of the evaporation (unless it is plugged into a float switch).

Another common addition to the Auto-Top-Off is some sort of supplemental dosing by either diluting the dose in the fresh-top-off-water, or it is commonly run through a KalkReactor before going in to the sump/tank. This allows all the water being added to the tank to be a saturated solution of Calcium Hydroxide (adding Calcium and Alkalinity) to help maintain the desired levels as well as raise the pH of the system.

 

[alrha]

Personally, on my 200gal system, i lose about 10-15 gal/week to evaporation.
I have a 6 gallon bucket in my stand with a MaxiJet (will probably change to a MiniJet) pump in it plugged into an Ultralife Float Switch.
it goes into an adapter to RO tubing then to a check-valve (to prevent backflow from the kalk-reactor).
From there is goes through a PM KalkReactor, and out from the reactor (as saturated Calcium Hydroxide) into my sump near the return.

The entire cost for such a set up would be:
PM KalkReactor = $260
MiniJet = $11
Ultralife Float Switch = $60
Total = $331 (+ Tubing and Valve)

 

[nyfireman3097]

The best dosing pump I have ever used was from http://www.innovativeaquatics.com/ Stan is the name of the owner and he is a GREAT guy there customer service is best to none I use about 5g every day to 2days and this thing kicks a$$

 

[Deanos]

The best dosing pump I have ever used was from http://www.innovativeaquatics.com/

I also use this dosing pump, which I acquired from Stan via eBay. I feed it using a 5g bucket (covered, of course :wink1: ) filled with kalkwasser. I have the dosing rate set to replace evaporated water. Depending on the room's humidity, I occasionally have to manually add 1/2 gallon of RO/DI to maintain the level in the sump.

 

[Hitsnorth]

I use a litermeter. I prefer a dosing pump because if you do have a failure you dont have a pump pushing in a lot of water. Even if the float switch on my litermeter failed there is no way for it to flood the tank.

 

[alrha]

i agree, but it adds to the cost.

 

[spykes]

SP3000 over aquamedic doser, roller peralist makes the line last longer. you use it over a digital timer. set how much you want to doser per day. this way i can set it to dose the amount i want over the time.

 

[Hitsnorth]

Might add to the initial cost but avoid one flood and it pays for itself.

 

[masterswimmer]

I've also got my topoff automated. I use the float switch in my sump with a Mag 7 in my RO/DI (55 gallon) container.

I have a fail safe built into it. I have my float switch plugged into an Intermatic Digital timer. I set the timer to come on for one minute every 4 hrs. (6 times in one day).

I have a ball valve on the tubing running into my sump that regulates the flow to about 1/2 gallon a minute. So my topoff can only topoff 1/2 gallon 6 times a day. This would equal 3 gallons/24 hrs. In the worst time for evap. (summer because I use fans for evaporative cooling) I only evap ~ 2 gallons a day. So there would be plenty of time to notice a problem with the auto topoff before any problem occured in the tank. It would only really 'overdose' one gallon in that day.

The tank is a 100 gal system so an extra 2 - 4 gallons of FW in one - two days wouldn't cause my salinity to sway too much. Besides it only delivers 3 gallons max in a day and needs 2 gallons of it.

Russ

 

[Tonyscoots84]

i still got a couple of project down the road but the auto top off is def. one of em...

 

[masterswimmer]

i still got a couple of project down the road but the auto top off is def. one of em...

Free tip: Move it up on your priority list! You'll be very glad you did. Takes sooooo much of the daily maintenance routine away and frees up time for other things.

Russ, yo' masta

 

[reefoman]

I prefer this setup, in my tanks working good from couple years...

 

[jackson6745]

i agree, but it adds to the cost.

Actually it would be cheaper than your topoff since you use kalk. You wouldn't need the kalk reactor. I had the litermeter for years, rock solid but loud. I don't know why I decided to change to the Tunze

It is easier to use a kalk reactor though and a lot less messy so i understand your choice

 

[reefoman]

Rich all day this setup working without kalk reactor, only in the night working with kalk reactor. For mine setup I use two solenoid valves, timer for kalk reactor, and one more water level sensor .

 

[jackson6745]

Mark could the soleniod fail and pump fresh water from the tap into your tank non-stop?

 

[reefoman]

I using very strong solenoid valve from pneumatic tools (this valve working with pressure max 450 psi) and is of course naturally close if something happens, but anyway yes Rich you right if solenoid fail, then water gonna fill it the system non-stop ...
I just thinking about extra kent manual shut-off valve.

 

[cali_reef]

Mark, don’t use Kalk water with the Kent Float valve, it will clog up the valve over time.

Rich, I use a similar set up as Mark except I use a 35 gallon drum in place of the RO/DI and it gravity feeds the sump. This will limit the max of 35 gallons (it is rarely that full) fresh water dumping in my sump if the solenoid should stay open, the scenario is almost impossible since I have two float switches for low level on and high level off and use another relay to control the solenoid, redundancy in this area is good since the float switch can fail or get stuck in the sump. The solenoid is built to fail in a “closed” position, the only way it can stuck in open would mean you have some type of foreign object contamination in your RO\DI water.

The 35 gallon reservoir can top off my system for about 7 days without refill in the winter, I would think you only need a 10 gallon container to auto top-off your system for a week. I'll find you the link for the solenoid valve later today.

 

[cali_reef]

Here is the link to the auto top off with float switch and solenoid.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=140759&perpage=25&pagenumber=1

I am stilling looking for the thread to built the dual float switch relay circuit for the added redundancy.

 

[cali_reef]

Found the diagram for the dual float switch circuit

http://reefcentral.com/gallery/showphoto.php?photo=18941&papass=&sort=1&thecat=500

Still can't find the thread

 

[alrha]

Actually it would be cheaper than your topoff since you use kalk. You wouldn't need the kalk reactor. I had the litermeter for years, rock solid but loud. I don't know why I decided to change to the Tunze

It is easier to use a kalk reactor though and a lot less messy so i understand your choice

wouldnt you still need the kalk reactor to dose it as saturated Calcium Hydroxide?
i thought the dosing pump just regulates how fast it doses, but you would still need the reactor, no?