TDS too high

[CassidyNZ]

My watermaker delivers between 600 and 700 ppm and the water tastes great. I’ve never seen 300ppm even with new membranes running in the tropics with gin-clear water.

Is water at 600ppm giving you a problem or is it just a random target?

[CosmicDrift]

Everything I have read, including the operation I structio s says it should deliver at 300-500ppm. It is often 800 and is now, today 1100+ and salty to taste.

[Sailmonkey]

Originally Posted by CosmicDrift

Yes, air bubbles randomly appear in the flow meter

You’ve got an air leak somewhere on the suction side. Cure the air leak and I’ll bet your tds measurements drops.

FYI for anyone looking for this unit in the web.

https://www.h2oonthego.com.au/

[belizesailor]

Originally Posted by CosmicDrift

Everything I have read, including the operation I structio s says it should deliver at 300-500ppm. It is often 800 and is now, today 1100+ and salty to taste.

300 to 500 is OK, but for a system in good condition 500 is on the high side. Over 800 is out of recommended range and becomes noticeable to taste. When TDS starts climbing toward 500 on a regular basis that likely indicates a developing problem...over 500 then youve definately got a problem.

My Spectra runs normally in the 200-300 range.

I dont need a TDS meter, my wife can taste it at about 700 PPM. [emoji849]

[SV THIRD DAY]

Originally Posted by CassidyNZ

My watermaker delivers between 600 and 700 ppm and the water tastes great. I’ve never seen 300ppm even with new membranes running in the tropics with gin-clear water.

Is water at 600ppm giving you a problem or is it just a random target?

BAD...BAD...BAD.....

You can't "Taste" the salt until it gets to the levels that it will damage your Kidneys!!! So if your TDS is over 500PPM, it's time for a new membrane, a membrane cleaning or you have a problem with your system flow rate.

[SV THIRD DAY]

Regarding High TDS Readings:
I have seen a growing number of mis-matched Hp Pump flow-rate vs Membrane size issues going on with new water makers.

The problem is that there is a minimum flow rate that needs to flow through the membrane and if you go below that, BOOM....the TDS shoots through the roof and you simply can't get down into the "normal" range of a new membrane and system.

For example.
I recently worked with a cruiser that had one of the "discount kits" and they sold him a 0.5GPM pump with a 40" RO Membrane. Right away I new it wouldn't work, but not wanting to be the "know it all on the dock here in La Paz" I walked through the troubleshooting with him and the company he was working with. Membrane two...same results. Finally when unable to help him figure it out I stepped in and let him know that the flow rate just wasn't enough to produce less than 500ppm water from the warm and higher salinity Sea of Cortez sea water. The "Fix" was to replace his 40" membrane with a 21", which solved the problem. The headache here is that this took 47 days to get straight, delayed his departure from La Paz, added a $900 Marina Bill to his cruising Costs and cost the client $850 in shipping and duty AND now he had a water maker with 1/2" the output than he though be bought and paid for!!!

So folks...before buying a discount water maker kit with membrane and pump matched pairs WAY Different than the other brands on the market (or before building your own)....do your homework. Don't get sucked into a Pump/Motor/Power/Membrane/Flow Rate promise that is too good to be true...because it probably IS!! I've seen about 7 of these screw-ups and I always feel bad for the client that bought assuming that someone selling something online knew what they were doing, which isn't always the case.

[CosmicDrift]

Thankyou Rich, I have found that one of the two ceramic pistons separated from the shuttle so the pump was at 50% output at best. That would explain why the pressure reg was almost closed to obtain flow and the high tds. Now the problem is getting parts and new membranes to Darwin AUS before departure day. Thanks

[SV THIRD DAY]

Originally Posted by CosmicDrift

Thankyou Rich, I have found that one of the two ceramic pistons separated from the shuttle so the pump was at 50% output at best. That would explain why the pressure reg was almost closed to obtain flow and the high tds. Now the problem is getting parts and new membranes to Darwin AUS before departure day. Thanks

Bingo....
Sometimes while out cruising find the problem is the easy part....getting the parts to fix it...well....

[CassidyNZ]

Originally Posted by SV THIRD DAY

BAD...BAD...BAD.....

You can't "Taste" the salt until it gets to the levels that it will damage your Kidneys!!! So if your TDS is over 500PPM, it's time for a new membrane, a membrane cleaning or you have a problem with your system flow rate.

So I have a three-cylinder CAT pump, three 21” membranes (installed in parallel), a 1.5hp electric motor. I also have flow metres on the raw water and product. The product flow at 1450rpm (pump speed) is about 110 litres per hour. But I was experiencing an overload on my inverter so I am presently reducing pump RPM by 20% in the belief that current draw will reduce enough for the inverter to keep up.

Your opinion would be of value.

[SV THIRD DAY]

Originally Posted by CassidyNZ

So I have a three-cylinder CAT pump, three 21” membranes (installed in parallel), a 1.5hp electric motor. I also have flow metres on the raw water and product. The product flow at 1450rpm (pump speed) is about 110 litres per hour. But I was experiencing an overload on my inverter so I am presently reducing pump RPM by 20% in the belief that current draw will reduce enough for the inverter to keep up.

Your opinion would be of value.

Without knowing the model of Pump, it's a SWAG (Scientific Wild Ass Guess) but a 1.5Hp motor can drive a 2.5GPM CAT Pump, so that's what I'm "ASSuMEing".

The pump is rated at 1750ish RPM, so when running it at 20% less RPMs you get 20% less flow rate. Since GPM output of the pump is directly proportional to pump RPM so that knocks 2.5gpm down to 2GPM. Membrane No 1 and No 2 plumbed in series are OK...and membrane No 3 is seeing about 1.2GPM....still ok.