making potassium (per) chlorate

[rogeryermaw]

excellent. thank you. i'll u/l when i get home from work.

[pyrojig]

 

His bucket cell is exclusively for converting KCl to KClO₃, so it uses an MMO anode and two titanium cathodes. We're saving the PbO₂ (or even Pt) for converting NaClO₃ to NaClO₄ and then exchange the product for whichever perchlorate is desired.

I'd be happy to get a copy of your PbO₂ lab manual, though. Thanks for offering !!!

WSM

 

 

Yes , it seems that there is a good reason that industry uses the Naclo3 to Naclo4 then double exchanged to Kclo4 with the Kcl ( Salting out process) . It can be done by the Kclo3 way , but i fear that if is way more work and may cost more to convert than following the commercial process .

 

The setup that WSM helped design was as said strictly for the making of Kclo3. I have many uses for that oxidizer. I DO however want to start making a shift to the KClo4 side of the tracks. I believe that the Na salt is the best approach and im looking forward to embarking on that road here soon now that I am getting settled in to the home we moved to.

Edited August 3, 2014 by pyrojig

[Thunder75007]

Gentlemen, I just want to thank you for the enormous amount of information presented here. I had already started making KCLO3 before I found this site. I am using clear acrylic 2 liter containers that I purchased at the Container Store and Wally World. I use a platinized titanium anode, 1.25”x 4”, with two stainless steel cathodes. I heat them up and push them through the acrylic top, then epoxy them in place. After the epoxy cures, I cover the epoxy with RTV Silicon. I do the same with my vent hose. At start up, I am pulling 13A @ 4.89vdc per cell. After filtering, re-crystallizing, and drying, I am getting 460 to 525 grams of KCL03 per cell, for a 156 hour run. I use no PH control and I found that I could drop the cell temperature as much as 30C simply by using a 12” fan on low blowing across them. I had to do something because at one point, the cell temperature rose up to 85C. This site has shown me how inefficient my set up is. I will be making changes.

 

Unlike you fellows, I am not producing this for pyrotechnics. I am producing the KCLO3 for targets. I am curious if KCLO4 would work as well. I shoot Tannerite targets, but when purchasing Tannerite at a store, expect to pay $10.00 per pound. Using one or two pounds per target, this gets expensive really quickly. I use a 70/30 mix of KCLO3 to Dark Aluminum. These targets can be set off using a .22LR instead of a high power rifle do to the increased sensitivity of the KCLO3 over the Ammonium Nitrate. I mix the components on site and shoot them immediately, as per the legal requirements to use Tannerite. Over a weekend with my buddies wanting to shoot targets too, we have gone through as much as fifty pounds of Ammonium Nitrate and Aluminum targets. Obviously we all had to pitch in to pay for the targets because I certainly can’t afford it!

 

Again, a big (THANK YOU) to all!

[pyrojig]

Im sure your not the only one who has similar interests . There are several folks that are looking for a cheaper way to produce those fun shooting targets . As per buying them from a store, it is about 100x more expensive than making your own( if you have access to the materials ) . Hands down AN targets are the cheapest if using fertilizer grade materials . Some folks are very lucky to know people or live in a area that isnt terror stricken and can purchase these w/o to much trouble . Others have to make it as described above , and or resort to other target mixs. I have shot both, and the kclo3-kclo4 /Al mixs seem to be much more powerful. The down side is the large amount of AL and Ant. trisulfide needed . THat is where your cost is. The kclo4 is of course the safer of the two, and still goes off with 22l w/o a prob. kclo3 is more sensitive and cheaper , so there is a tradeoff , but one to consider. It all comes down to experience and lots of study ( books) of these materials in order to perform safe mixing ( non static) and handling /.

[WSM]

Gentlemen, I just want to thank you for the enormous amount of information presented here. I had already started making KCLO3 before I found this site. I am using clear acrylic 2 liter containers that I purchased at the Container Store and Wally World. I use a platinized titanium anode, 1.25”x 4”, with two stainless steel cathodes. I heat them up and push them through the acrylic top, then epoxy them in place. After the epoxy cures, I cover the epoxy with RTV Silicon. I do the same with my vent hose. At start up, I am pulling 13A @ 4.89vdc per cell. After filtering, re-crystallizing, and drying, I am getting 460 to 525 grams of KCL03 per cell, for a 156 hour run. I use no PH control and I found that I could drop the cell temperature as much as 30C simply by using a 12” fan on low blowing across them. I had to do something because at one point, the cell temperature rose up to 85C. This site has shown me how inefficient my set up is. I will be making changes.

 

Unlike you fellows, I am not producing this for pyrotechnics. I am producing the KCLO3 for targets. I am curious if KCLO4 would work as well. I shoot Tannerite targets, but when purchasing Tannerite at a store, expect to pay $10.00 per pound. Using one or two pounds per target, this gets expensive really quickly. I use a 70/30 mix of KCLO3 to Dark Aluminum. These targets can be set off using a .22LR instead of a high power rifle do to the increased sensitivity of the KCLO3 over the Ammonium Nitrate. I mix the components on site and shoot them immediately, as per the legal requirements to use Tannerite. Over a weekend with my buddies wanting to shoot targets too, we have gone through as much as fifty pounds of Ammonium Nitrate and Aluminum targets. Obviously we all had to pitch in to pay for the targets because I certainly can’t afford it!

 

Again, a big (THANK YOU) to all!

 

The first half of this post fits in here. The second half would probably fit better in another thread dedicated to the subject discussed (or possibly in the HE section).

 

Let's keep apples, apples; and oranges, oranges. Thanks.

 

WSM

[Thunder75007]

Sorry WSM. I was just wanting to thank you guys for the great information. I did not mean to mix up the fruit. Best Regards.

[WSM]

Sorry WSM. I was just wanting to thank you guys for the great information. I did not mean to mix up the fruit. Best Regards.

 

Hi Thunder75007,

 

No problem, I would rather keep the topics separate.

 

I (we all, really) appreciate your gratitude and are glad to help. Keep posting and share your experiences with us.

 

WSM

Edited August 4, 2014 by WSM

[pex]

70/30 chlorate is dangarous sensitive. Look out with this stuff

[WSM]

Gentlemen, I just want to thank you for the enormous amount of information presented here. I had already started making KCLO3 before I found this site. I am using clear acrylic 2 liter containers that I purchased at the Container Store and Wally World. I use a platinized titanium anode, 1.25”x 4”, with two stainless steel cathodes. I heat them up and push them through the acrylic top, then epoxy them in place. After the epoxy cures, I cover the epoxy with RTV Silicon. I do the same with my vent hose. At start up, I am pulling 13A @ 4.89vdc per cell. After filtering, re-crystallizing, and drying, I am getting 460 to 525 grams of KCL03 per cell, for a 156 hour run. I use no PH control and I found that I could drop the cell temperature as much as 30C simply by using a 12” fan on low blowing across them. I had to do something because at one point, the cell temperature rose up to 85C. This site has shown me how inefficient my set up is. I will be making changes.

Unlike you fellows, I am not producing this for pyrotechnics.

Again, a big (THANK YOU) to all!

 

Hi Thunder75007,

 

Did you ever take pictures of your setup? It would be interesting to see what it all looks like. Plus, we can offer suggestions for improvements if we can see where you're starting from.

 

Have you ever considered substituting a less expensive MMO anode for your platinized one and save the platinum anode for converting chlorate to perchlorate? It seems that this is becoming the current thinking in this forum.

 

Also, it sounds from your description, like you're running more than one cell. Is that true, or are you running one at a time but keeping others in the wings?

 

Let us know when you get a chance. Thanks.

 

WSM

[WSM]

I'm getting ready to attend the PGI Convention in Mason City, Iowa; and may not be able to follow these threads as much as normal in the next week or so. If any of you are going and run into me, come up and say Hi (I love to chat about electrochemistry; as if you didn't know already). It's fun to tie faces to the handles here.

 

WSM

[WSM]

70/30 chlorate is dangarous sensitive. Look out with this stuff

 

It may be overly sensitive, especially in large quantities. I'd keep targets made of such materials small for safety's sake.

 

WSM

[Thunder75007]

Thanks for the advice and information Pyrojig, WSM, and PEX. So far, I have kept the targets of KCLO3 to 16 grams due to my pucker power kicking in. Even at this size, my palms were sweaty. In consolation though, the grounding strap on my wrist had a great connection, considering that it was wet!

 

I found the thread on exploding targets so I won't discuss it here anymore.

 

I do have multiple cells and I run two at a time with one for a spare, but again, they are only 2 Liters each. I have no pictures currently but I will try to post some for you in a week or so. We shall see....

 

I just got in some Titanium plates today along with a 115 to 220vac transformer, and another 5vdc 50A power supply. I have an SMC process chemical pump but it uses 200vac. All of the equipment I work on uses odd voltages. I know that the pump will run on 208 but I am not sure about 220vac. I plan to use this pump for PH control, if the 220 does not fry it. I will be making a bucket cell out of an empty pool chlorine bucket. The thick, high density polyethylene should be perfect for this, being chemical resistant and has a melting point of 133c. I think that a small bead of silicon in the top groove of the bucket lid will help to get a better seal, to prevent salt creep. I will try long skinny cathodes to hopefully keep the solution better stirred. On my little 2 liter cells I find a variance of 5 to 6c, from the top of the the cell to the bottom of the cell. I have read that a larger cell has a much greater problem. I am considering a MMO anode on this build also. Once this guy is up and running, I plan to try to make KCLO4 in the small cells.

 

I have never studied anything like this before and I am finding all of the Pyro information fascinating. Reading about shells, mixtures, charges, colors, burst types, etc., I can see how it could become addictive as a hobby or as a profession.

[WSM]

Thanks for the advice and information Pyrojig, WSM, and PEX. So far, I have kept the targets of KCLO3 to 16 grams due to my pucker power kicking in. Even at this size, my palms were sweaty. In consolation though, the grounding strap on my wrist had a great connection, considering that it was wet!

I found the thread on exploding targets so I won't discuss it here anymore.

I do have multiple cells and I run two at a time with one for a spare, but again, they are only 2 Liters each. I have no pictures currently but I will try to post some for you in a week or so. We shall see....

I just got in some Titanium plates today along with a 115 to 220vac transformer, and another 5vdc 50A power supply. I have an SMC process chemical pump but it uses 200vac. All of the equipment I work on uses odd voltages. I know that the pump will run on 208 but I am not sure about 220vac. I plan to use this pump for PH control, if the 220 does not fry it. I will be making a bucket cell out of an empty pool chlorine bucket. The thick, high density polyethylene should be perfect for this, being chemical resistant and has a melting point of 133c. I think that a small bead of silicon in the top groove of the bucket lid will help to get a better seal, to prevent salt creep. I will try long skinny cathodes to hopefully keep the solution better stirred. On my little 2 liter cells I find a variance of 5 to 6c, from the top of the the cell to the bottom of the cell. I have read that a larger cell has a much greater problem. I am considering a MMO anode on this build also. Once this guy is up and running, I plan to try to make KCLO4 in the small cells.

I have never studied anything like this before and I am finding all of the Pyro information fascinating. Reading about shells, mixtures, charges, colors, burst types, etc., I can see how it could become addictive as a hobby or as a profession.

 

I would be surprised if your 200Vac pump wouldn't work just fine on either 208, 220 or even 240Vac. I have a small pump from Japan rated at 100Vac and it works fine at 120Vac. About the transformer, remember that VA in equals VA out, so when you double the voltage output, the amperage output will be cut in half. If the current draw of the device on the secondary side of the step-up transformer is 5A the current draw of the transformer will be 10A.

 

Good electrical practices say we should load the circuit to no more than 80% of it's capacity, so bare that in mind also. Another point about electricity to remember, larger voltages require thicker insulation and higher currents require larger conductors. So, to be safe, if your device uses 220Vac 10A, and you're feeding it from a 120Vac circuit through a step-up transformer (and it's the only thing on the circuit breaker), the current load will be 20A and the leads to the transformer should be 10 AWG (good to 30A, conservatively) and the recommended circuit breaker will be 25A, minimum.

 

The more details you can give us, the more correct the suggestions we can give. And since everyone is watching; if one of us goofs, the others will catch it and offer corrections.

 

This is a friendly place.

 

WSM

[pyroChile]

Gentlemen, I just want to thank you for the enormous amount of information presented here. I had already started making KCLO3 before I found this site. I am using clear acrylic 2 liter containers that I purchased at the Container Store and Wally World. I use a platinized titanium anode, 1.25”x 4”, with two stainless steel cathodes. I heat them up and push them through the acrylic top, then epoxy them in place. After the epoxy cures, I cover the epoxy with RTV Silicon. I do the same with my vent hose. At start up, I am pulling 13A @ 4.89vdc per cell. After filtering, re-crystallizing, and drying, I am getting 460 to 525 grams of KCL03 per cell, for a 156 hour run. I use no PH control and I found that I could drop the cell temperature as much as 30C simply by using a 12” fan on low blowing across them. I had to do something because at one point, the cell temperature rose up to 85C. This site has shown me how inefficient my set up is. I will be making changes.

 

Unlike you fellows, I am not producing this for pyrotechnics. I am producing the KCLO3 for targets. I am curious if KCLO4 would work as well. I shoot Tannerite targets, but when purchasing Tannerite at a store, expect to pay $10.00 per pound. Using one or two pounds per target, this gets expensive really quickly. I use a 70/30 mix of KCLO3 to Dark Aluminum. These targets can be set off using a .22LR instead of a high power rifle do to the increased sensitivity of the KCLO3 over the Ammonium Nitrate. I mix the components on site and shoot them immediately, as per the legal requirements to use Tannerite. Over a weekend with my buddies wanting to shoot targets too, we have gone through as much as fifty pounds of Ammonium Nitrate and Aluminum targets. Obviously we all had to pitch in to pay for the targets because I certainly can’t afford it!

 

Again, a big (THANK YOU) to all!

 

 

Hello Thunder!

 

can you make chlorate with platinized anode? further, with 4,98v.., because chlorate is made with with maximun 3,5v

What kind of electrolyte initial?

thanks for sharing your experience

Best,

=)

[Thunder75007]

WSM, Thanks for the advice. I tested the pump last night and all is well so far. The pump is only 16watts and the transformer is 100w so I'm golden. That should give me 50w on the 220vac side. Thanks for reminding me about the amperage doubling on the (UP) side of the configuration. Also, I stated that the pump was a SMC but this one is an IWAKI. I just also came into possession of two almost new SMC Process Pumps, but they are pneumatic. After looking up the price on eBay, I think that I need to sell'em!

 

Also, I am only up to page 108 in this thread so if this is known information, forgive me. I buy my KCL from Home Depot also but not all of them carry it. I search the stores on-line to find out which stores in my area have it in stock. This prevents allot of wasted time and frustration. I have also found that the stores in my area keep it by the exit door on pallets.

 

Hello PyroChile. Yes, I use Platinized Titanium for the anode and high quality Stainless Steel for the cathodes. I bought the cheap $33.00 4" x 1.25" anode from eBay. As I stated, running two of these cells, I have harvested right at 1 kilo of high quality KCLO3 per week. This is after washing, re-crystallization, and drying. I use a PC Power Supply and tie all of the 5vdc lines together. After finding this site, my knowledge has increased tremendously and I realize that they can produce allot more. I use KCL salt to start with. When I top-off the cells, I have been adding more KCL saturated solution instead of just R/O Water. I also take a reading of the cell temperature and then heat the solution up to this temperature to prevent thermal shock. I must admit that this cell design and operation has become sort of a hobby, although I really can't afford another one! I already have too many irons in-the-fire! If you have not read this thread from the beginning, I suggest that you do so. Good Luck in your endeavors.

[pyrojig]

Lucky guy!!!! have fun out there!!

[WSM]

WSM, Thanks for the advice. I tested the pump last night and all is well so far. The pump is only 16watts and the transformer is 100w so I'm golden. That should give me 50w on the 220vac side. Thanks for reminding me about the amperage doubling on the (UP) side of the configuration. Also, I stated that the pump was a SMC but this one is an IWAKI. I just also came into possession of two almost new SMC Process Pumps, but they are pneumatic. After looking up the price on eBay, I think that I need to sell'em!

 

The wattage stays the same (100w in = 100w out). According to Ohm's law, both E/IR and P/IE apply, where:

 

E = electromotive force (voltage)

I = intensity (current measured in amperage, or amps)

R = resistance (measured in ohms)

P = power (measured in watts)

 

And, I'm sorry, but Yes, math is required here...

 

The specifications you mention for your pump make me think you could use a 6 foot piece of 18 guage lamp cord to feed it, with no worries.

 

I have several IWAKI pumps of a couple of different types. They're great and I'm glad to have them. What type of pump is yours?

 

WSM

[WSM]

Hello Thunder!

can you make chlorate with platinized anode? further, with 4,98v.., because chlorate is made with with maximun 3,5v

What kind of electrolyte initial?

thanks for sharing your experience

Best,

=)

 

Well, that's not strictly accurate. Industry standards usually specify 3.6 Vdc (with graphite or MMO), but in my experience (with MMO and titanium) the voltage can vary between about 2.7 Vdc and 5.5 Vdc without too much trouble.

 

The whole thing is not black and white; there are MANY variables, including but not limited to:

 

voltage (or electron pressure, if you will)

current (or the volume of electrons)

internal cell resistance (which impedes the flow of electrons and is converted to heat)

and let's not forget the element of time.

electrode size, shape, gaps, configuration, method of attachment, material, etc. etc.

temperature

pressure

 

And none of this takes into consideration the myriad chemical reactions taking place simultaneously as things increase, decrease, are generated in or dissipated from the cell; all at the same time.

 

When we chart and graph all these things over time we get only a tiny glimse of what's happening in there.

 

Lucky for us we don't have to understand it thoroughly to get it to work. We just feed the cell what it needs and harvest the desired product when it's done. BUT, to optimize the process, we need to understand it better (hence, our interest in all those variables).

 

Whew! I'm exhausted.

 

WSM

[pyroChile]

 

Well, that's not strictly accurate. Industry standards usually specify 3.6 Vdc (with graphite or MMO), but in my experience (with MMO and titanium) the voltage can vary between about 2.7 Vdc and 5.5 Vdc without too much trouble.

 

The whole thing is not black and white; there are MANY variables, including but not limited to:

 

voltage (or electron pressure, if you will)

current (or the volume of electrons)

internal cell resistance (which impedes the flow of electrons and is converted to heat)

and let's not forget the element of time.

electrode size, shape, gaps, configuration, method of attachment, material, etc. etc.

temperature

pressure

 

And none of this takes into consideration the myriad chemical reactions taking place simultaneously as things increase, decrease, are generated in or dissipated from the cell; all at the same time.

 

When we chart and graph all these things over time we get only a tiny glimse of what's happening in there.

 

Lucky for us we don't have to understand it thoroughly to get it to work. We just feed the cell what it needs and harvest the desired product when it's done. BUT, to optimize the process, we need to understand it better (hence, our interest in all those variables).

 

Whew! I'm exhausted.

 

WSM

Ok, so 3,6v...but the anode is platinized..maybe there is perchlorate..in adition, this anode can resist that amperage?

 

 

Best,

 

=)

[pyroChile]

WSM, Thanks for the advice. I tested the pump last night and all is well so far. The pump is only 16watts and the transformer is 100w so I'm golden. That should give me 50w on the 220vac side. Thanks for reminding me about the amperage doubling on the (UP) side of the configuration. Also, I stated that the pump was a SMC but this one is an IWAKI. I just also came into possession of two almost new SMC Process Pumps, but they are pneumatic. After looking up the price on eBay, I think that I need to sell'em!

 

Also, I am only up to page 108 in this thread so if this is known information, forgive me. I buy my KCL from Home Depot also but not all of them carry it. I search the stores on-line to find out which stores in my area have it in stock. This prevents allot of wasted time and frustration. I have also found that the stores in my area keep it by the exit door on pallets.

 

Hello PyroChile. Yes, I use Platinized Titanium for the anode and high quality Stainless Steel for the cathodes. I bought the cheap $33.00 4" x 1.25" anode from eBay. As I stated, running two of these cells, I have harvested right at 1 kilo of high quality KCLO3 per week. This is after washing, re-crystallization, and drying. I use a PC Power Supply and tie all of the 5vdc lines together. After finding this site, my knowledge has increased tremendously and I realize that they can produce allot more. I use KCL salt to start with. When I top-off the cells, I have been adding more KCL saturated solution instead of just R/O Water. I also take a reading of the cell temperature and then heat the solution up to this temperature to prevent thermal shock. I must admit that this cell design and operation has become sort of a hobby, although I really can't afford another one! I already have too many irons in-the-fire! If you have not read this thread from the beginning, I suggest that you do so. Good Luck in your endeavors.

Ok, is remarkable that anode can withstand 13 amp...

 

 

Best,

 

=)

[Thunder75007]

WSM, the IWAKI is a EH-B30FF-200R3-E4 with a EHC-B200R controller. The SMC pumps are PAF3413-P12-X30. I thought that the IWAKI was the super expensive on of the group. Boy was I wrong!

 

Math?!... What's that?! Oh yeah, what I ment so say was is that I have less amperage available on the 200vac side, not the wattage.

 

100watts @ 115v = 0.869 amps

100watts @ 220v = 0.454 amps

 

Thanks for keeping me straight...

[Arthur]

I've used Iwaki bellows pumps in a previous career, they are stunningly good for pumping measured amounts per stroke, they are usually run from a timer. I used them from pH1 to pH11 they just work.

[Thunder75007]

OK gentlemen. I have a story to tell that I just experienced. I am freaked out, I don't believe this, but I have the proof. I do not understand what happened or how it happened. With the hundreds of hours of research, my own months of experimentation, many kilos of KCL03 made, and the great information on this site, I thought that I had making KCLO3 down. Well, I just got my mind blown. Please Help!!

 

Last Sunday evening, I cleaned out my two 2ltr cells as usual, recharged the remaining solution with KCL and R/O to saturation and re-started them. While working Monday evening, I hit one of the cells with the ladder and it fell over. Considering they are water tight I simply stood it back up. Bad mistake. At some point in the night a salt bridge must have formed, because it shut down my power supply. The next day when I checked on them, the solution was dark brown/black. I dumped everything cleaned the stainless cathodes, (they rusted), cleaned the Platinized anode, created new KCL and R/O water liquor, and re-started. I use 300 to 325 grams of KCL to 1 liter of R/O water. The cells run at 45 to 50c

 

Wednesday morning I noticed that in one cell, the solution was light yellow, (normal) but the other was crystal clear! Each cell was pulling 11 amps so I was not sure what was going on. I decided to let them run and see what happened. One cell solution is still light yellow, the other still crystal clear. I let the cells run through the weekend and next week. I would top them off with more KCL solution as needed. Friday morning, over a week later, the crystal clear cell was light black. I checked the amperage and it was pulling 2 amps! WTF??? The other cell, (light yellow), is still pulling 8 amps. I shut down the light black cell and chilled it to 32 F, but when I filtered it through my vacuum Buchner funnel, instead of KCLO3, it looked like salt. I boiled it all down to re-crystallize and I carefully watched the cooling process.

 

When the liquor hit 182 F, I saw tiny little short hairs/fibers drop out of solution. For a reference, I would say no more than 0.5 grams.

When the liquor hit 162 F, I saw powder drop out of solution. About ¼ of a grain of sugar in size. When the liquor hit 133 F, I saw the first signs of KCLO3 crystals, but still mainly powder drop out of solution. When the liquor hit 120 F, I saw mostly tiny KCL03 crystals drop out of solution. I then chilled it down to 32 F.

After vacuuming until no more liquid was present but not totally dry, it weighed in at 363.4 grams. I dried out a few grams of the precipitate and mixed it with sugar. When lit, I had a beautiful fast burning purple flame. I then mixed some with dark aluminum and WHOOSH, good flash. I have not moved on to making KCL04 and I am not familiar with it, but it appears to me that this stuff is 90 to 95% KCLO4.

 

Herein is the problem. How on earth could this have happened?! How could this be mostly KCLO4? If it is not KCLO4, what is it? I thought that all of this was impossible! Apparently I don’t understand as much as I thought that I did. I did not think that you could go from KCL to KCLO4 without stopping.

 

Any ideas? Thanks……….

Edited August 9, 2014 by Thunder75007

[pex]

Have you tried test with methyleen blue? Than you can't find it out. It's possible that you have a part of kclo4. It's only a bit fast but it's not inpossible.

[Thunder75007]

Hey Pex. No I do not have and methyleen blue. I was going to pick some up later when I try to convert the KCL03 to KCL04, but I thought that the burn test showed what I have.

 

After sleeping on it all knight, there are two things different about this run than ever before. The temperature here was cooler during this run and I did not have to add much makup KCLO3 and R/O water. Also, I normally shut down the cells every 7 days so that cleanup and restart are on the weekend. It takes too much time to get everything done on in a single work night. Because of the power supply shut down, I ran this cell 9 1/2 days and the other is still going. I was so busy last weekend that I actually forgot that I did not do the usual shut down/restart on the cells. There was not enough to harvest for the trouble anyway. I have edited my statement above to reflect this. I am going to stop the other cell this morning and check it. I will post my findings later.