When do you change your prefilter?

[drewlamb]

Looking for input on changing the prefilter to see if there's another simpler way that doesn't have so much filter changing. I use the filter I'm already concentrating with for the initial prerinse, then switch to a dedicated wash filter for the wash cycle. I use this same wash filter all season. After the wash I switch to a new filter for the final rinse and leave this one in for the next concentrate. Is this overkill? Wash water goes through the prefilter too, correct? Would it be ok to switch to a new filter before the wash cycle and just leave that one in for the rinse and next concentrate day? Seems like all that permeate would wash the soap out really well and keep it from getting into the next batch of sap to go through the RO. Thanks.

[maple flats]

I start each day with a fresh pre-filter and most times that is good for the whole day, but ocassionally I need to change it in late season. I change it if the feed pressure drops below 20 psi. My typical feed pressure is 70+ PSI. That filter stays in (except on those rare times I need to change it early) until I finish washing and rinsing the RO, then I put a new one in the next day. I think last year I had 1 time I had to change it during the day.
Pre-filters are cheap, why would you use the same one for a whole season? I buy mine a case or 2 at a time (either 20, 24 or 25 filters depending on brand)

[Mark-NH]

At $6 per filter, fresh filter to start each day

[drewlamb]

Maybe my longwinded question wasn't clear... I use a new filter for each boil but switch out for one devoted to the wash cycle. The machine instructs you to switch the filter then, which I do, but I was always reluctant to keep it in for the next boil figuring it may get fouled with soap and get into the next batch of concentrate. So I end up switching for the wash, THEN put a new filter in that stays through the next time I concentrate.

Exactly, seems like a lot of switching right? Which is why I ask. New filter each boil would be a good deal simpler.

[johnallin]

I use the filter from that day when I do a wash. I don’t keep a dedicated filter just for washing. Probably missing something but it just doesn’t make sense to me.

Actually I don’t know why you even need a filter for a wash cycle. On my Hobby CDL, the filter is after the pump and just before the membrane. If I’m using permeate, what is there to filter?

[Russell Lampron]

I use a dedicated pre filter for washing. I use a new pre filter when I start concentrating and if the sap is extra dirty I'll change it mid cycle if it gets clogged up. When I'm done concentrating I remove and throw away the dirty prefilter. For the first wash cycle of the season I put in a new pre filter for washing and rinsing. When I'm done washing and rinsing I save that one and put a new one in to concentrate again. You'd be surprised how dirty that wash pre filter gets as the season goes on. I sometimes change it out during the season if gets nasty enough.

You guys that are paying $6 per pre filter need to shop MES. I paid less than $3 each for a case of them last season. I think the actual price was $2.65 each but I don't remember the exact number. The thing that I do remember is that it was cheaper than Amazon.

[SeanD]

I tried keeping a dedicated soap wash filter this season. I was able to use it for two washes, but after the second time it was starting to brown up so, I pitched it. I've tried to use the same filter from the day's boil for the wash cycle, but my low pressure switch often kicks - like I can't even get the machine to stay on when I first hold the button in. It's an nasty business swapping the filter out once soap is in the canister, so I've just put a new on in before the wash. With this heat, warm cloudy sap, and low sugar. I'm going through lots of filters.

Dave I'm curious how you get such a high psi on your front end. My best is only ever 20 psi and during the second pass on a warm day, it's not unusual to drop below 10 (but still run). My 275 gallon feed tank bottom sits about 12"-18" above the RO intake.

Sean

[maple flats]

Back when I just used the onboard feed pump it was like 20-30 psi, I now use a 1 hp SS sprinkler booster pump between the RO and the source, that gives me 70-75 psi and seems to give my a slight increase in total flow, maybe 3-5%. The way I have mine set up I have 3 sources possible. 2 of my 3 sap tank being used are plumbed together and they feed to #1 valve, I have a re-circulation line from my head tank, that feeds #2 valve and my permeate tank feeds #3 valve. In use if I want to start recirculating I just open open #2 at the same time as I close #1. Then I go to the RO and back the pressure off so as the concentrate hits the membranes it doesn't shut the RO off on high pressure. When I am ready to start my cold permeate rinse I close which ever is open 1 or 2 and open #3. All 3 valves are within easy reach. At the 2 sap tanks each has a valve, I usually empty one, then the other. If sap is flowing good, I leave both tank valves open so I then have 415 gal + 545 gal capacity. I only use that 3rd tank if both are full or in use, and a load of bought sap comes in. Then to use that I have another pump line that I can hook into my re-circulate line so I can pump that to the RO. I used the Deer Run pump alone for 2 years and sometimes it was slow to get it to prime even though I filled the housing. The 1hp pump I use is primed by simply opening the permeate valve and that pushes thru to the RO, then I close valve #3 and open #1.

[bill m]

I start every day with a new prefilter no matter how much sap has been through the old one. I buy them by the case and pay about $4.00 each.