Spectra Catalina 300 pre filters in tropical waters

[LifesBetterWhenYoureBeating]

Thanks to @Tellie I now have a working watermaker and a much happier girlfriend (as I can now shower regularly!). However, when I run the WM after it's been sitting idle for 5 days, I always get bad smelling water for the first couple minutes.

Spectra recommends keeping 3 sets of pre filters when in tropical waters, soaking one set overnight in fresh water, then letting it dry and putting that in place when the WM is shut down. But since every time I run the WM there's a fresh water flush at the end, the filters in the housings will be basically soaking in fresh water, no? I wonder if these recommendations are for systems that don't have a fresh water flush module?

Also, I had to disable the pre-filter check on my MPC 5000 (it was preventing my system from running even with brand new filters), so I'm wondering how often should I be replacing my pre filters?

Any other tips about caring of my pre filters (or the overall system) in tropical waters would be greatly appreciated.

Thanks in advance

[Tellie]

Don't get mad but I don't recognize your CF handle. Once I know who this is it might all come back to me. I'm getting a bit old. (a lot old)

One of my biggest pet peeves.

Forget what Spectra said. You're not properly freshwater flushing (FWF) your Catalina300. 95% of the time a customer complains that upon startup of their system after a few days sitting idle that they get that rotten egg smell it is a FWF issue. Depending upon how old your Cat300 is will depend a bit on how to set the FWF up correctly. Before I can give you the right instructions on how to do this proper FWF set up I need to know if your system uses a speed drive to adjust speeds or if your system is old enough to use the on/off function of the feed pump motor to adjust the FWF. I would suggest an Email to me with a few pics of the feed pump module and what program your MPC5000 has. You can also post the pics here for others to see and learn.
The idea for a proper FWF is to have your brine discharge read 1,000PPMs or lower. You will need a handheld TDS meter for this as well. The vast majority of watermaker owners do not understand this, most installers, and unfortunately too many manufacturers, either don't care or just don't know. This has become more evident the past few years as more watermaker companies are popping up and this exact issue comes our way far more often than it ever used to.
Every boat will be different and every watermaker regardless of make MUST be set up properly or you will lose your membranes sooner than later. Your system FWFs after each use and every five days of non-use. Your house pressure pump feeds the watermakers charcoal filter to provide the fresh water under pressure to help with the flush. This is where the uninitiated get lost. Every freshwater pump is going to deliver different flows and different pressures. It would not be unusual to have two identical boats and two identical freshwater pumps, and two identical watermakers flushing for different time periods to achieve a proper flush. If for example your watermaker is demanding 3gpm for a FWF and your house pump is only capable of delivering 2.5gpm, the watermaker wants it's other .5 gallon and will make it up by drawing salt water up through the intake thru hull. In this situation you could flush this system for ten hours with 2,000 gallons of fresh water and you will still not have FWF your system properly. The feed pump must either be slowed done to match the intake from the house pump or in your case perhaps the feed pump motor will be set up to start and stop multiple times as not to over demand your house pump. Once this balance is achieved where there is no saltwater intrusion or over flushing, your system will be ready to test the brine discharge. After your system is saturated with salt water, flush your system for three minutes. Stop the system. Test the brine discharge water. If it is 1,000PPMs or below you are good. If it is higher run the FWF for one minute more and test again. You should be down to a more realistic 500PPMs once flushed well. Once you are there and have the amount of time it takes to get there you set your controls to run the FWF for that time. It may be less than five minutes it may be more. It is not the run time that matters but the amount of freshwater needed to do a proper flush.
Again, a pet peeve of mine. I hear all kinds of wonderful about all kinds of systems out there. Next time a watermaker representative is trying to sell you the newest and greatest technology for cheap. Ask him if he knows how to properly set up the FWF like the above. If he doesn't, then he's a salesman not a watermaker tech, and there are far more salesmen out there than those that actually know what they are talking about. If he does, 50% chance they learned it from us.

[Tellie]

PS, You had other questions. Your pressure sensor for the filters is bad, that's why you are getting the "Service Pre-filters" alarm early. Bypassing it as you have is perfectly fine and won't hurt the system. You will also scrap the Spectra suggestion that you soak your pre-filters. You should be changing your pre-filters every 30-45 days if you are using your system every 2-3 days on average. Just rinse the pre-filter with about the same water pressure from a shower head. You'll, see the shumutz roll off. No scrubbing, no bleaching, and no dragging them behind your boat. Let them dry and put them back into rotation. When a pre-filter gets a spongy feel when squeezed it is time to replace it. I recommend that you take a set of pre-filters for every month you intend to be gone out cruising. This is probably more than you need but sometimes filters do get clogged quickly as they are doing what they are supposed to do in nastier waters. One Charcoal filter for every six months change out. (The six months count down starts the day the filter gets wet, regardless of how many times you do or do not use your watermaker. Every six months once wet.)

[LifesBetterWhenYoureBeating]

Originally Posted by Tellie

Don't get mad but I don't recognize your CF handle. Once I know who this is it might all come back to me. I'm getting a bit old. (a lot old)

One of my biggest pet peeves.

Forget what Spectra said. You're not properly freshwater flushing (FWF) your Catalina300. 95% of the time a customer complains that upon startup of their system after a few days sitting idle that they get that rotten egg smell it is a FWF issue. Depending upon how old your Cat300 is will depend a bit on how to set the FWF up correctly. Before I can give you the right instructions on how to do this proper FWF set up I need to know if your system uses a speed drive to adjust speeds or if your system is old enough to use the on/off function of the feed pump motor to adjust the FWF. I would suggest an Email to me with a few pics of the feed pump module and what program your MPC5000 has. You can also post the pics here for others to see and learn.
The idea for a proper FWF is to have your brine discharge read 1,000PPMs or lower. You will need a handheld TDS meter for this as well. The vast majority of watermaker owners do not understand this, most installers, and unfortunately too many manufacturers, either don't care or just don't know. This has become more evident the past few years as more watermaker companies are popping up and this exact issue comes our way far more often than it ever used to.
Every boat will be different and every watermaker regardless of make MUST be set up properly or you will lose your membranes sooner than later. Your system FWFs after each use and every five days of non-use. Your house pressure pump feeds the watermakers charcoal filter to provide the fresh water under pressure to help with the flush. This is where the uninitiated get lost. Every freshwater pump is going to deliver different flows and different pressures. It would not be unusual to have two identical boats and two identical freshwater pumps, and two identical watermakers flushing for different time periods to achieve a proper flush. If for example your watermaker is demanding 3gpm for a FWF and your house pump is only capable of delivering 2.5gpm, the watermaker wants it's other .5 gallon and will make it up by drawing salt water up through the intake thru hull. In this situation you could flush this system for ten hours with 2,000 gallons of fresh water and you will still not have FWF your system properly. The feed pump must either be slowed done to match the intake from the house pump or in your case perhaps the feed pump motor will be set up to start and stop multiple times as not to over demand your house pump. Once this balance is achieved where there is no saltwater intrusion or over flushing, your system will be ready to test the brine discharge. After your system is saturated with salt water, flush your system for three minutes. Stop the system. Test the brine discharge water. If it is 1,000PPMs or below you are good. If it is higher run the FWF for one minute more and test again. You should be down to a more realistic 500PPMs once flushed well. Once you are there and have the amount of time it takes to get there you set your controls to run the FWF for that time. It may be less than five minutes it may be more. It is not the run time that matters but the amount of freshwater needed to do a proper flush.
Again, a pet peeve of mine. I hear all kinds of wonderful about all kinds of systems out there. Next time a watermaker representative is trying to sell you the newest and greatest technology for cheap. Ask him if he knows how to properly set up the FWF like the above. If he doesn't, then he's a salesman not a watermaker tech, and there are far more salesmen out there than those that actually know what they are talking about. If he does, 50% chance they learned it from us.

No worries, Tellie! I was the one with the system that had the salinity constantly increasing and production dropping, courtesy of leaks in my Clark pump caused by the crumbling white annular ring o rings in the valve block.

I'd already adjusted my fwf duration following your instructions (from a previous thread), and today I ran my system for 1h in the morning, so now I went back to measure the ppm of the brine discharge again, and it looks like my 4 minutes of fwf are enough as it was 850. Do you think increasing it to 5 minutes would help with the bad smell in the water immediately after startup?

I'll also be washing my filters and letting them dry after every use, as you suggest.

Also, I have no need to make water every 3 days so I'd rather do it every 5 days. Or is that too long a time for it to be idle?

[LifesBetterWhenYoureBeating]

All my pre filters were due for replacement so I did that two days after I last ran my system. Today I ran it again as it's been 5 days since the last run, but even with fresh filters the product water was still a bit smelly in the beginning, although not as bad as before.

I'll try running again in 3 days to see if I'd still get the bad smelling water in the beginning