Help me determine topoff container size.

[reefsahoy]

Considering doing either a 10 G cube or possibly a peninsula nano, prob a WB 15G.  How much evaporation are you guys getting on your cube or peninsula aquarium. ?  
 

thx

[skippylou]

WB Cube 10 here, I see between ~8-16oz daily depending on time of year.

[DSA65PRO]

Quote

Are you manually topping off? Salty Zoo dot Com has a handy calculator to determine how much salinity change you can do without damaging livestock. If you can put up with the look, there is a Soda Bottle top off. It sets on the rim of your tank. When the level drops, air enters the bottle and releases water. Think of one of the big upside down Five Gallon Water Dispensers. An Automatic ATO will be a bit of overkill.  If you go that way, limit your reservoir to Salty Zoo’s calculation and what will Overflow your tank. On my 23 liter capacity Biocube I use a Four Liter Food Jar, candy came in it. I highly recommend the Prism ATO’s The only thing that messes them up is Bright Light shining on them, IE Metal Halide, or Sunlight. Clean the sensor once a month with a soft toothbrush. 

 

[reefer_evo5]

Evaporation depends on the temperature of the room where the tank is and also how much surface agitation you have something that would help with less evaporation is a piece

of glass over the tank or acrylic I have a 20 gallon tank with a lot of surface agitation and my house temperature is almost always 72 degrees. I currently use 2 gallons of top off water in about 5 days I use a ATO since manually topping off gets old real quick. 

[BioBoy16]

I have always heard u want to keep your top off container relatively small. If ur ato fails u don't want your room to flood. I'd err on the smaller side and refill the ato as needed. 

[travoose]

2 hours ago, BioBoy16 said:

I have always heard u want to keep your top off container relatively small. If ur ato fails u don't want your room to flood. I'd err on the smaller side and refill the ato as needed. 

I've got to second this.  I have a twenty gallon tank with a three gallon reservoir....I add about two gallons to the reservoir twice a week...but I enjoy knowing that if something fails, I won't have as much of a mess on my hands.

 

[Superdave]

I have a 20ish gallon tank and use a 1.25 gallon slim profile refrigerator water container as my top off vessel.  Is very similar to this one:  

 

https://www.campingworld.com/arrow-home-products-h2o-oasis-1.25-gallon-beverage-dispenser-92924.html?utm_source=google&utm_medium=ppc&utm_campaign={Campaign}&gclid=CjwKCAjwvsqZBhAlEiwAqAHElQ42cusElpLIy8fRmfTgwkapVwuxyDKWCSBfkM8dpilHSQbjFDRC1hoC6ToQAvD_BwE&gclsrc=aw.ds

 

It lasts me for over a week usually, though I check it more often than that.  ATO has cut off sensor so don't have to work about pump running dry.  I have a glass lid over the tank and that drastically cuts back the evaporation.  

[mcarroll]

On 4/20/2022 at 11:45 AM, BioBoy16 said:

I have always heard u want to keep your top off container relatively small. If ur ato fails u don't want your room to flood. I'd err on the smaller side and refill the ato as needed. 

I've always been a pretty vocal proponent of "right-sized" gear, and that goes for ATO reservoirs too.

 

Calculate how much "extra" water your system can hold in the event that the ATO would fail and do a 100% dump.  
 

Formula:  

(L"xW"xD")/231 = gallons

 

So (making up an example here) if there's an inch of space at the top of your (14*14*12/231=) 10 Gallon aquarium, then you'd want a reservoir no bigger than (14*14*12/231=) 1 gallon.  (.85 gallons, technically.)

 

 

Still use a low-failure ATO!!  But should the worst happen, you can be confident that it won't really be as bad as it could have been.  I.e. Flood; total wipeout; etc.  Just a water change and the tank is back to normal....livestock probably not even phased by it.  (Similar to a big storm dumping a lot of freshwater at once on a reef.  It happens!  No biggie!)