Help! precise drip/doser for top-off?

[Debbie64]

So, I've got a gravity top off going: Acrylic cube, fed with RO via auto liquid level controller, john guest ball valve and tube dripping into the fuge at 1 drip per 1.5 seconds. Or so.

It was actually doing fine before I started running kalk through it. (I'm trying to keep my pH up.) Basically, I can't seem to get it to keep a constant drip. It's fine for a day or so and then it slows down. So then sump level drops, pH drops. It's hard to get adjusted again. It's driving me slowly insane.

I'm sure there's a dosing pump out there that I can hook up to the cube to keep the drip constant. Isn't there? I'd rather not spend $300, but I was looking at this: http://www.marinedepot.com/md_viewItem.asp?idproduct=AQ4511

Does anyone use this? Will it do what I want it to do? Is there anything out there that will?

Since I'm adding the kalk slurry to the top off cube, it has to drip in slowly so for obvious reasons, I can't use a unit that works via a float or pressure switch.

Thanks!

Debbie

 

[bertoni]

The moderator in the chemistry forum uses a dosing pump, I think a Reef-Filler, that should work. A search there should confirm the brand name. I bought used Master-Flex pumps for my systems.

 

[AllenFord_SC]

The peristaltic pumps like the one you mentioned are perfect for what you need...... to a certain extent. If you notice it has a fixed rate of .8 GPH. Not good unless you are evaporating that much water per hour, which you aren't. There is however a way to fix that.

Simple solution: Float valve. http://www.marinedepot.com/md_viewItem.asp?idproduct=JB5111
The float valve will turn the pump on and off when needed.