Tunze Osmolator and Nilsen Reactor

[johns]

I got a Nilsen reactor today and have a Tunze Osmolator I would like to control it with.

The Nilsen comes with a valve on top to restrict/control the output flow of kalk to the tank. Seems like a good idea but I'm wondering - is it ok to restrict the flow from the reactor so it drips SLOWLY into the sump tank? or will this be hard on the osmolator pump to do this?

 

[blgreef]

I also used to runa reactor from the tunze , and i found.

Restricting the pump will work but the pump will not last as long, not a major issue as they are relatively cjeap to replace.

The 10 minute cut off timer will be a problem, and depending on evap and drip rate you may not be able to add enough water before this timer turns the pump off. One way around this is to turn off the osmo unit via tmer now and again to reset it, again not ideal.

I have now decided to go for a peristaltic pump and drip the kalk over a 14 hour period to make better use of the kalk.

 

[Ruminari]

Just curious. Why would running a Nilsen reactor be any different then running the Kalk chamber that you can buy with the osmolator? Shouldn't you be able to just open up the Nilsen reactor and let the osmolator top off like normal?

 

[johns]

Just curious. Why would running a Nilsen reactor be any different then running the Kalk chamber that you can buy with the osmolator? Shouldn't you be able to just open up the Nilsen reactor and let the osmolator top off like normal?

Just dont want to add the kalk too fast or too much volume all at once to avoid pH spikes.

The input to the sump from the osmolator goes directly to my return chamber/return pump. So I'm asuming the kalk solution that gets added via the osmolator is pretty much going into the display (after a bit of dilution in the return chamber)

 

[MiddletonMark]

I'd wonder about precipitation [even dripping] over time with the kalk right before the pump. I don't know ... but it would make me a little paranoid.

My osmo seems to run regularly but for quite short periods ... I'd be interested to see how much a spike you'd get from Kalk. I'd guess you could run a little less concentrated Kalk and still be fine ... though might not want to do that.

I'm looking at that same situation ... so happily tagging along. Let us know how you make it work

 

[dougc]

I feed my MRC Nilson reactor with my Osmolator. The Osmolator just pumps water through the reactor. It works fine this way for me. The Osmolator turns on a couple of times an hour and runs for maybe 30 seconds. I don't restrict the output of the Nilson in any way.

 

[rvitko]

It should work, lots of people do it. I see no need to restrict the outflow as it only pumps usually a quart at a time, the sensor is very precise so the water doesn't drop an amount that is even really visible before the pump turns on. The flow rate of the pump is about a quart a minute so it is pretty slow.

 

[johns]

Mark-

I think the safest/best way to use the the Osmolator is to plump the output from your reservoir directly to the chamber where the sensor is located (Roger, correct me if I'm wrong). In my case (and probably most cases) that the return chamber.

I have the same concerns you have about adding kalk directly to the return chamber since it has less of a dilution factor before entering the pump and also the display tank. But everyone is right about the amount of water the Osmolator feeds to the sump at any given top-off event - it is fairly small (mine runs about 10 or 15 seconds at a time). But I have little frame of reference for this since I am new to this. So I am still a little paranoid about messing up my return pump or spiking the tank with kalk.

The only other thing i can think of is to direct the top-off kalk to the in-sump refugium that is directly in front of my return chamber. That would give a little more dilution and the kalk will have to go through the bubble trap before it hits the return. I just dont know if there are other concerns with that, and I hope the sensor located in a separate chamber as the top-off addition wont screw things up.

 

[blgreef]

I would Worry that adding it to fast would allow percipitation so you would not get the best effect and in the worse case may even be counter productive.

Adding kalk drip by drip in a high flow area would help prevent local percipitation and hence you get more millage from the kalk.

used to drive a kalk reactor via the osmo pump but have now moved to adding it one drop per second during lights out and the PH is more stable and does not have the peaks when it was added quickly also there is no local percipitation in the sump, when the flow rate of kalk was high then a large chunk of the kalk percipitated.

have a sheet of glass under a fan to help cool the tank the kalk was added to th water flow over this sheet of glass; when added too quickly the glass quickly got covered by percipitation

 

[grim]

Ok, I've used the osmolator with my nielsen for a while, stopped, and went back, and finally stopped (just because I have a peristaltic pump now).

If you have a large non-baffled sump where the entire sump volume falls and rises with evaporation and top off, the osmolator can inject much more kalkwasser than you really want it to, enough to cause a very high localized pH spike in the sump and causing precipitation on the pump impellers in the sump.

You must have a sump with a return chamber where only a small portion of the sump rises and falls with evaporation and top-off. The osmolator sensor is very sensitive, and in this configuration will work *very* well at adding only a small amount when necessary.

My sump is non-divided and somewhat large, about 25 gallons total volume with a large surface area. Once the osmo tripped, it would push a little over 2 cups of kalkwasser into the sump (measured by first timing the length of the top off cycle, than reproducing it by draining the effluent into a cup for the same amount of time).

I'm using the peristaltic now because I needed to have more control over my kalk dosing (I don't need 100% top off with kalk). Currently running about 250ml/hr drip.

jb

 

[johns]

Ok, I've used the osmolator with my nielsen for a while, stopped, and went back, and finally stopped (just because I have a peristaltic pump now).

If you have a large non-baffled sump where the entire sump volume falls and rises with evaporation and top off, the osmolator can inject much more kalkwasser than you really want it to, enough to cause a very high localized pH spike in the sump and causing precipitation on the pump impellers in the sump.

You must have a sump with a return chamber where only a small portion of the sump rises and falls with evaporation and top-off. The osmolator sensor is very sensitive, and in this configuration will work *very* well at adding only a small amount when necessary.

My sump is non-divided and somewhat large, about 25 gallons total volume with a large surface area. Once the osmo tripped, it would push a little over 2 cups of kalkwasser into the sump (measured by first timing the length of the top off cycle, than reproducing it by draining the effluent into a cup for the same amount of time).

I'm using the peristaltic now because I needed to have more control over my kalk dosing (I don't need 100% top off with kalk). Currently running about 250ml/hr drip.

jb

Grim. That makes good sense to me. Luckily, my sump is baffled and the Osmolator sensor is in the final, smaller return chamber. So the amount of kalk added at any one time should be fairly small. If Roger's pump rate of ~1 qt/min is correct, I'm estimating that I'll add probably 1/2 cup at each top-off.

That said, I still worry a little about messing up my Eheim return pump. So I guess right now, I'm trying to decide if I should direct the the 1/2 cup or so of kalk into a different chamber of the sump. Like in the refugium that is directly in front of the return chamber, or into the very first drain chamber. The drain chamber is the furthest from the return and has the most turbulence, so it would probably be best in that regard. Howver, it does house the skimmer, so I could wind up messing with that pump. It's only a Sedra 3500 though, so not as expensive as the Eheim return pump.

 

[grim]

You don't need to top off in in the return chamber, you are on the right track thinking about topping off at the first sump chamber (or the area with most water movement). I actually used to pump my return up to the overflow chamber on my tank. It cut back the flow rate a little bit (slower fill due to the head height) and gave the kalkwasser a little more time to mix before it hit something it could precipitate on (skimmer, return pumps, heaters). It also eliminated any possibility of siphon if the check valve on the nielsen reactor should fail.

While calcium buildup on impellers is a pain in the neck, it doesn't at all damage anything, an hour in vinegar once every month or two generally takes care of the problem.

I'm in the process of building a new (much larger) system, and will use my osmolator in this way. I'd like to get rid of the peristaltic to simplify things.

jb

 

[johns]

You don't need to top off in in the return chamber, you are on the right track thinking about topping off at the first sump chamber (or the area with most water movement).

My only concern was that topping off somewhere other than the return chamber (or wherever the Osmolator sensor is located, for that matter), might cause a slight increase in the amount of kalk solution being added at any one time.

I dont know if this makes sense, but I was thinking that topping off in the drain chamber or in the overflow box (GREAT IDEA BY THE WAY! - I MAY HAVE TO TRY THAT) might cause a bit of a 'lag-time' between when the sensor trips open and then closes (ie. takes some additional amount of time for the sensor way down in the return chamber to 'see' the additional volume that you are adding, hence larger and longer volumes added at any one time).

Does it make sense? Maybe not as big of an issue as I was thinking? But I dont know.

 

[rvitko]

Please keep in mind that the osmolator should alwys pump up to the tank, the reservoir water level will likely be above the height of the sump water level and this means that even after the pump turns off the water will continue to siphon. I generally recommend having the osmo output directed to the overflow boxes this way it mixes thoroughly. In most cases the amount added is so miniscule that no ill effect would be noticed if the flow was appropriate. The only real caution is if you were to take out water for a water change or adding a coral or fish or removing a pump or rock, the amount added could be enough to cause a real problem.

 

[johns]

Please keep in mind that the osmolator should alwys pump up to the tank, the reservoir water level will likely be above the height of the sump water level and this means that even after the pump turns off the water will continue to siphon.

I've heard a few cautions about the creation of a siphon and, quite frankly, don't really know if I understand it. I have been using my osmolator dumping top off RO water into the sump return chamber for a few months now with no siphon problem ever. And yes, the reservoir bucket water level is generally higher than the level in the return chamber, but the osmolator pump sits at the BOTTOM of the reservoir bucket, so the pump is NEVER higher than the water level in the return.

Am I missing something here? If so, could you please help me understand.

 

[rvitko]

It is dangerous to do so, if the hose end is below the water level of the reservoir the potential exists for a siphon to be created.

 

[johns]

It is dangerous to do so, if the hose end is below the water level of the reservoir the potential exists for a siphon to be created.

Doesn't the hose end need to be below the pump itself and not necessarily below the water level?

I remember when I was first installing the Osmolator and I created a siphon once when I let the hose drop to the ground and it was below the pump housing. But if the hose is 1.5 -2 feet above the pump housing, how can a siphon be created? I'm sorry, I'm not trying to be argumentative, but I am trying to understand.

You are talking about a siphon from the reservoir to the tank and not vice-versa, right? Because I could see maybe the potential for a siphon from the tank into the reservoir bucket if the hose end is submerged - is that possible?

 

[rvitko]

I just wouldn't take the chance, it is designed to pump up to the tank. Yes, a siphon could occur in the opposite direction too so the hose should always end above the water surface.

 

[johns]

I just wouldn't take the chance, it is designed to pump up to the tank. Yes, a siphon could occur in the opposite direction too so the hose should always end above the water surface.

Well I cant say I understand completely. But I guess it does give me more of a reason to try what grim suggested and bring the hose right up to the overflow.

As I mentioned earlier, my only concern with that was I thought I'd be adding more volume at once when I add up there rather than down in the return chamber.

 

[MiddletonMark]

I do the Osmo into my overflow box ... and it is great. There is a little lag-time as mentioned - but given the sensor trips with VERY little drop in an area that refills fast ... it still doesn't run more than 30 seconds max.

But yes, a little lag time ... but my plan for my Kalk use