evaporation water top off ????

[AlrightCool]

what are some suggestions to auto top off tank i tried making a bottle top off by just haveing it above the tank with a tube line to where i want it top off but i guess the weight of the water just pushed it out no matter what i did any DYI things i could do i mean its only for a 10 gallon but i dont want to have to keep putting water in everyday im running out of good water lol dont have an ro unit yet and the skimmer has to almost be perfect water lvl for it to work reason why i want it to be at a steady lvl stupid nano skimmer lol

Here is an updated pic of my tank still cycling coming along pretty well

 

[AlrightCool]

picture actually needs to be flipped lol damn computer

 

[ChrisRD]

I usually use a dosing pump for topoff. It's not a perfect solution since evap rates tend to vary but IME it's simple and reliable. It's also easy to hide the topoff reservoir in a remote location when using a peristaltic pump (good against high head and no worries of back syphon).

HTH

 

[Len]

Coming along nicely.

Without a sump, you have very little room for errors. I wouldn't try a timed (e.g. dosing pumps) or dripped method.

You can try building a Nurce-style top off:
http://www.reefs.org/phpBB2/viewtopic.php?t=27285

But IMO, your best bet is a good float switch and a low-volume pump like a Aqua Lifter (cheap). To be safe, I would set up two float swtiches: One to detect if the water level is low (which activates the top-off pump to fill the tank with freshwater) and another switch to detect if the water level is too high (which turns off the pump just in case the first float switch isn't working accurately).

 

[ChrisRD]

While I would normally never disagree with Len's vastly superior reefing knowledge, I think have a different view here...

Lots of folks use dosing pumps (particularly medical feeding pumps) as topoff/dosers for small tanks with no issues. I've done this myself on several small tanks including a 20 gallon nano (no sump) and had no problems over the course of several years.

Also, one precaution you need to take with float switches - even with a double switch setup - is to avoid a skimmer design/setup that could potentially dump water out of the system in an overflow situation. A float switch topoff has the potential to continually add fresh water, kalkwasser or whatever you are using for topoff as the skimmer overflows. This can result in a rapid drop in salinity or a disastrous pH spike (if you're using kalkwasser for topoff) in the system.

IMO all topoff systems have their ups and downs - you just need to know what the limitations are and plan accordingly.

JMO of course...