Ro system question

4everwet · 09/07/2007, 08:03 PM

My RO setup came with a 3gallon holding tank. Should I eliminate it? Wondering if it could begin to get nasty inside it or stagnant, and I would never know it. I guess what the question really is could it eventually cause more TDS?

tmz · 09/07/2007, 08:26 PM

I have one on my system. Is it a metal sealed jug with a bladder for pressure. I use mine to feed an outlet in the kitchen for drinking water.I tee it off the ro line whcih goes to my roughneck rubbermaid resevoir. It is sealed and I don't believe it can lead to tds build up since it only receives purified water and it is the first water to backfill my resevoir so it is always fresh.

AZDesertRat · 09/07/2007, 09:57 PM

Yes it will build up over time. When you use a RO or RO/DI for drinking water too it cycles or comes on and off according to the pressure and/or volume in the bladder tank. This leads to short cycling which leads to TDS creep. Frequent short runs filling the bladder tank with the initial TDS creep water start to add up to high TDS in the tank.
That being said I use a 14 gallon bladder tank in my system anyway just because I like the convenience of having pressurized water on demand. My RO puts out a TDS of 5 to 6 when it is allowed to run a few minutes but when it is just topping off the bladder tank it can be higher. I find the TDS gets up to about 25 in the bladder tank if I do not empty it on a regular basis. I store my DI water in 5 gallon drinking water jugs so I make it a point to empty 3 or 4 jugs before I refill them so I completely drain the bladder tank and it refills with fresh low TDS water.

tmz · 09/08/2007, 12:12 AM

AZdesert rat, I follow your point. Mine is plumbed on a tee which branches to my resevoir. When I draw water out of the resevoir( which is a daily occurence of two two gallon bucketts at a time which go into my kalk/top off drip resevoir ) the 3 gallon jug empties completley in response to a float valve in the main resevoir.

4everwet · 09/08/2007, 08:29 AM

AZ, my ro system does not have a DI. Would I get lower TDS with one? My LFS said it wasn't needed, but it seems like everyone uses them. He said when it became exhausted it could leach resin in the water..? Is this true or false? And also can I trust a float valve to shut off the water going from my ro to my topoff res? Is the pressure after the ro low enough that the float will have no problem?

AZDesertRat · 09/08/2007, 12:13 PM

DI is a must in most cases if you plan to keep a sucessful reef system.
Yes exhausted resin does release weakly ionized substances. The key is to have a TDS meter and use it often so you catch and replace your DI cartridge when you begin to see any reading other than 0 on a regular basis. DI resin lasts a long time if you have a good RO system.
Floats are fine for a holding reservoir like brute trash can or similar. I would not depend on one for my autotopoff system in my sump though. You would want multiple float switches with a space between them so they are not constantly switching on and off, short cycling your RO and raising the TDS. Even in a trash can I would fill it until the float shuts it off then shut the supply off and let it drain down quite a bit before I opened the supply so you get a nice long RO run to reduce TDS creep.

tmz · 09/08/2007, 03:42 PM

AZDesertrat, Thanks
for the tips on managing TDS creep. Very helpful.
Tom

4everwet · 09/08/2007, 05:32 PM

Yea thanks for the info AZ! Very much appreciated!

09/07/2007, 08:03 PM	#1
4everwet Registered Member Join Date: Dec 2005 Location: oklahoma Posts: 165	Ro system question My RO setup came with a 3gallon holding tank. Should I eliminate it? Wondering if it could begin to get nasty inside it or stagnant, and I would never know it. I guess what the question really is could it eventually cause more TDS?

09/07/2007, 08:26 PM	#2
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	I have one on my system. Is it a metal sealed jug with a bladder for pressure. I use mine to feed an outlet in the kitchen for drinking water.I tee it off the ro line whcih goes to my roughneck rubbermaid resevoir. It is sealed and I don't believe it can lead to tds build up since it only receives purified water and it is the first water to backfill my resevoir so it is always fresh. __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.

09/08/2007, 12:12 AM	#4
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	AZdesert rat, I follow your point. Mine is plumbed on a tee which branches to my resevoir. When I draw water out of the resevoir( which is a daily occurence of two two gallon bucketts at a time which go into my kalk/top off drip resevoir ) the 3 gallon jug empties completley in response to a float valve in the main resevoir. __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.

09/08/2007, 03:42 PM	#7
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	AZDesertrat, Thanks for the tips on managing TDS creep. Very helpful. Tom __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.

09/07/2007, 09:57 PM	#3
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Yes it will build up over time. When you use a RO or RO/DI for drinking water too it cycles or comes on and off according to the pressure and/or volume in the bladder tank. This leads to short cycling which leads to TDS creep. Frequent short runs filling the bladder tank with the initial TDS creep water start to add up to high TDS in the tank. That being said I use a 14 gallon bladder tank in my system anyway just because I like the convenience of having pressurized water on demand. My RO puts out a TDS of 5 to 6 when it is allowed to run a few minutes but when it is just topping off the bladder tank it can be higher. I find the TDS gets up to about 25 in the bladder tank if I do not empty it on a regular basis. I store my DI water in 5 gallon drinking water jugs so I make it a point to empty 3 or 4 jugs before I refill them so I completely drain the bladder tank and it refills with fresh low TDS water.

09/08/2007, 08:29 AM	#5
4everwet Registered Member Join Date: Dec 2005 Location: oklahoma Posts: 165	AZ, my ro system does not have a DI. Would I get lower TDS with one? My LFS said it wasn't needed, but it seems like everyone uses them. He said when it became exhausted it could leach resin in the water..? Is this true or false? And also can I trust a float valve to shut off the water going from my ro to my topoff res? Is the pressure after the ro low enough that the float will have no problem?

09/08/2007, 12:13 PM	#6
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	DI is a must in most cases if you plan to keep a sucessful reef system. Yes exhausted resin does release weakly ionized substances. The key is to have a TDS meter and use it often so you catch and replace your DI cartridge when you begin to see any reading other than 0 on a regular basis. DI resin lasts a long time if you have a good RO system. Floats are fine for a holding reservoir like brute trash can or similar. I would not depend on one for my autotopoff system in my sump though. You would want multiple float switches with a space between them so they are not constantly switching on and off, short cycling your RO and raising the TDS. Even in a trash can I would fill it until the float shuts it off then shut the supply off and let it drain down quite a bit before I opened the supply so you get a nice long RO run to reduce TDS creep.

09/08/2007, 05:32 PM	#8
4everwet Registered Member Join Date: Dec 2005 Location: oklahoma Posts: 165	Yea thanks for the info AZ! Very much appreciated!