New-to-Hobby folk---you DO need an ATO

[Sk8r]

(auto topoff, to keep your salinity rock solid---bouncing salinity can kill your fish)---and there's a good discussion in Lighting, Filtration and Other gadgets, on the ins and outs of various brands of ATO. It's hard to find a good one, and while it should be a slam dunk to set up a basic float switch and a reservoir...not everything works as advertised.

 

[SantaMonica]

It's neat that a lot of tanks come with ato reservoirs, which I did not see ten years ago.

 

[sivob]

Some of these all in one tanks seem to be cheating compared to what we had to figure out 15 years ago. These new tanks are giving me the itch to get back into the hobby.

 

[Belgian Anthias]

Automatic top off

Based on evaporation, the water level? Based on Salinity? Based on Electronic conductivity?

Based on a float switch, the water level, seems to me not to be a good idea. What if there is a small leak.?

EC of seawater is high, I think this makes it difficult to make it accurate enough
for a reasonable price, and without constant maintenance of the probes.

By using LED, evaporation is greatly reduced. Covering the tank, the sump or and other refugia where possible will limit evaporation.
Through experience one knows approximately how much water evaporates every day. One can use an adjustable drip tap, such as a baxter in the hospital (ask a nurse) to drip the water (also for lime water). What is available is used to check the salinity. In this way, overdosing in the event of a small leak, even after a few days of absence, is prevented. The advantage is that it is very cheap.

 

[Dan.]

I love my Tunze 3155, sure beats manual topping off and salinity stays rock steady.

 

[Sk8r]

Evaporation can drive calcium supplementation via kalk. Preventing evaporation may not be a good idea for that reason.

 

[albano]

Automatic top off

Through experience one knows approximately how much water evaporates every day. One can use an adjustable drip tap, such as a baxter in the hospital (ask a nurse) to drip the water (also for lime water). What is available is used to check the salinity. In this way, overdosing in the event of a small leak, even after a few days of absence, is prevented. The advantage is that it is very cheap.

+1"¦. Been using drip line top off on multiple tanks for over 30 years"¦ without fail or problems.
ATO fills a 10g holding tank and drip lines using plastic adjustable air line valves replace evaporated water.