Do you trust gravity or electronic based ATO.....or both?

[Smite]

I ask because my newly set up and cycling 180 is blowing through top off water and it doesn't even have lights yet. I've been topping off manually and going through about 2.5g per day! My planned 10g reservoir is not going to cut it with 4 day supply. I left no room for a larger reservoir (current one was going to fit nicely behind the tank with the same width as my external overflow) my wife wants to see nothing outside the tank's stand.

I've been considering using a 55g food grade black barrel on a stand on my side yard to gravity feed into my tank. I've ran a gravity fed ATO system on a QT system for well over a year with no issues, but that was in the garage NOT my living room

If I go this route I'll probably have the 55g gravity feed my AA reservoir, and have that top off my tank with my Tunze ATO system to avoid salt creep. But how reliable are these gravity float valves really? Would you trust one?


Whats everyone prefer out there anyway?

 

[Tastee]

I use both. In my QT I just use a simple home made gravity fed ATO with a float valve. My DT is a RSR 250 and I use the stock 8 litre ATO which is also gravity fed with a float valve. I use a Neptune ATK to keep the ATO full, running the PMUP once a day to top it up. I use an optical sensor in the sump return to warn me if the float valve gums up and stops filling.

I like the gravity fed float valve as it continuously tops up the tank for evaporation, maintaining salinity as close to perfect as you can get.

 

[Ranjib]

I use my own controller and smart ato micro. I dont think its a bad idea to use gravity fed ato, as long as the circuit is good.

 

[Smite]

I use both. In my QT I just use a simple home made gravity fed ATO with a float valve. My DT is a RSR 250 and I use the stock 8 litre ATO which is also gravity fed with a float valve. I use a Neptune ATK to keep the ATO full, running the PMUP once a day to top it up. I use an optical sensor in the sump return to warn me if the float valve gums up and stops filling.

I like the gravity fed float valve as it continuously tops up the tank for evaporation, maintaining salinity as close to perfect as you can get.

So the RedSea Reefers use gravity fed top off then? Thats reassuring. My fear is it failing open due to salt creep and dumping the entire ATO into the sump.

 

[Tastee]

So the RedSea Reefers use gravity fed top off then? Thats reassuring. My fear is it failing open due to salt creep and dumping the entire ATO into the sump.

Yes, I think all the range do, just varying the size of the reservoir as the tanks increase in size. Mine is 8L/2.1G, so will only keep the tank topped up for ~3 days, which is why you also need something to top it up if you want to keep using it.

The RSR sump only runs about 1/3 full so there is plenty of room in case of the float failing open. For a single failure the small ATO means it can only dump a small amount of water. If you are refilling it manually this means you should never be at risk of a flood.

The ATO outlet is below the top of the sump, but the top of the ATO is above the sump top. That means in my case where I refill the ATO automatically, I could flood it, but it would take several days. I ‘might’ notice this due to decreased salinity but then again it may still be within tolerance. My floor leak sensor however would be triggered so that would alert me.

I’ll keep this in mind - hadn’t thought of that risk, so thanks! My easiest protection would be a high level optical sensor in the sump, but I would need to buy another FMM for that. I could also reduce my ‘When ON’ statement for the ATK to alert me to an unusually high ATK draw. Hmm.....