Kalk reactor...

[Texreefer]

pressurized reactor gravity fed from large resevoir, effluent from reactor into sump through mecanical float switch that shuts off using pressure

[matt]

Despite Jim's success with using a float switch/powerhead arrangement, I would still recommend the dosing pump. There are many horror stories about a stuck float switch and a flooded sump. If you're just using water for top off, it'll knock down your salinity but that's it. If you accidentally dump a few gallons of KW into your sump at once, you could wipe out the tank. That's what happened to Minh in Corpus. I guess it depends on your tank size; if you have a 200-300 gallon system, a few gallons might not be a big deal. My tank is so small that even a 1 gallon overdose would probably kill alot of animals. The dosing pump makes it impossible to accidentally pump excess KW into your tank, and since it's a steady drip rather than a periodic stream, there is essentially no variance in salinity or ph.

I like these dosing pumps so much I'm thinking about getting another one to dose my home made 2-part Ca/Alk supplement. I think I need about 50 ml/day (about 2 oz) and the newer innovative aquatics pump can do that, it actually goes down to .5 ml/day per channel for 2 channel dosing.

[Texreefer]

my tank evaporates less than a gallon a week on 120 total gallons,, i would have to really up my evaporation rate to go with a doing pump... not sure if i want to do that or not.. good info though,,,, safeurwehr... not trying to hijack your thread, hope this info helps you as well

[JimD]

matt, Im not using a powerhead to dose the tank, Im using an Aqualifter vacuum pump to deliver fresh water to the reactor, check the link,. I was using a high dollar parstaltic pump and it worked fine until the bushings wore out and got way too loud. The vacuum pump/float switch is a great alternative for folks that just dont have the coinage for the more expensive gear.

[matt]

Oh yeah, that's different, looks like a good idea. Still, though, 3.5 gallons/hour would kill me if the float switch stuck. Originally I was going to use a set of stainless steel sensors and a solenoid hooked up to my R.O. filter, which has a similar flow rate. Supposedly the sensors are more reliable than a float switch, but I never ended up using it because I bought the medical dosing pump.