woodnaquanut
Active member
Problem w/ that is it's not good for RO/DI to run 'just a little' so there would have to be a system to wait till TO was almost empty.
Oh yea, my tank is not very close to the RO/DI. I knew there was another reason!
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Problem w/ that is it's not good for RO/DI to run 'just a little' so there would have to be a system to wait till TO was almost empty.
Oh yea, my tank is not very close to the RO/DI. I knew there was another reason!
woodnaquanut
Active member
I've heard it's hard on the membrane. Perhaps urban legend?
For sure when you start up the RO output is not as clean as it gets. My RO starts out at about 15ppm on the TDS meter. After it runs for a few minutes it is outputting 1ppm. This uses up much less DI resin per gallon produced.
If it was topping off, the RO would almost always be in the high TDS range and go thru DI resin fast compared to the amount of water it produced.
Now there is the convenience factor! It would be sweet to not have to fill up TO.
Then it's important to have some fail-safe controls so the ATO doesn't go nuts and flood the tank w/ FW. Right now, assuming my dinky pump could do it, the TO is limited to 7g. Corals might get ****ed but I don't think it'd kill them. I know there wouldn't be a flood.
<< edit Funny the **** added by RC! >>
Reef Bass
colors and textures
John is referring to "tds creep". Whenever one starts ro/di water production, the initial water out of the filter has some tds. Mine usually starts around 8-10. I let it run for 5 to 10 minutes and it drops to 0. I don't need any algae fertilizer and would prefer this water not enter my system.
My experience backs up conventional wisdom for membrane longevity. Make lots of water infrequently versus a bit often. I'll make 20+ gallons at a time and my current membrane has been lasting very well. There are good threads about this on RC.
And as we've discussed before, temperature can affect production rate and waste water to pure water ratio.
My experience backs up conventional wisdom for membrane longevity. Make lots of water infrequently versus a bit often. I'll make 20+ gallons at a time and my current membrane has been lasting very well. There are good threads about this on RC.
And as we've discussed before, temperature can affect production rate and waste water to pure water ratio.
Dapg8gt
New member
^^^I support this statement =).
It's a good practice to waste the first minute or two of your make up water so you don't get it into your system.
I installed a 3 way valve that I dump the post membrane water for about a min so it never even hits my di. I think I'm going to add a membrane flush kit also with my next membrane change on my spectrapure unit just to flush the deposits away and hopefully extend the life of my membranes a little bit. Spectrapure initially said it's not needed but now all of the sudden they changed gears and recommend it.
It's a good practice to waste the first minute or two of your make up water so you don't get it into your system.
I installed a 3 way valve that I dump the post membrane water for about a min so it never even hits my di. I think I'm going to add a membrane flush kit also with my next membrane change on my spectrapure unit just to flush the deposits away and hopefully extend the life of my membranes a little bit. Spectrapure initially said it's not needed but now all of the sudden they changed gears and recommend it.
woodnaquanut
Active member
Important point Ken made. As we are likely to experience water rationing this summer/fall, it would be nice to maximize good to waste water.
My RO/DI is outside. I've been giving some thought to how to heat the incoming water to increase productivity. Also it would be nice not to worry about the unit freezing!
Anybody have a working system to heat the unit or incoming water?
I've been thinking about some sort of enclosure for the RO/DI and heat from a seed starting mat like --well RC wouldn't let me post the URL! Just do a search for "seed starter mat"--.
Thoughts welcome.
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lokii_37
New member
I don't dump the first few minutes of my RO because I know my DI will take care of it. No need to waste the water that has already gone thru the membrane. In an effort to conserve more water I have been thinking about adding another membrane to the waste of my first. Then another DI filter.
A awhile ago Ron posted in a RO discussion about some anti condensation valves for toilets of something like that. You can hook the hot and cold water lines to it and adjust the temp so you don't have water leaking off your valves onto the floor. Also so you can have water at the perfect temp for the membrane.
A awhile ago Ron posted in a RO discussion about some anti condensation valves for toilets of something like that. You can hook the hot and cold water lines to it and adjust the temp so you don't have water leaking off your valves onto the floor. Also so you can have water at the perfect temp for the membrane.
Reef Bass
colors and textures
John I think the seed mat idea for cool locations is a good one.
Trying to be ultimately efficient with where warmth is required, maybe a small heating pad around the membrane would be sufficient?
Lokii, I run dual DI and dual carbon canisters in my water filter. I measure my tds on the input to and output from the filter. And I have tds creep despite dual DI. There are postings about why this occurs.
Trying to be ultimately efficient with where warmth is required, maybe a small heating pad around the membrane would be sufficient?
Lokii, I run dual DI and dual carbon canisters in my water filter. I measure my tds on the input to and output from the filter. And I have tds creep despite dual DI. There are postings about why this occurs.
woodnaquanut
Active member
Water temp. out of the pipe is a little lower in winter than summer. This might effect production somewhat. I know the filter's environment changes quite a bit summer to winter. That is my reasoning for heating the entire filter but have emphasis on the RO membrane. Also, I'm both lazy and forgetful! I'd like to not have to worry about the unit freezing. It's a PIA to take it inside every time I think there will be a cold enough night.
I have noticed very little TDS creep on final output. I have a BRS 'value +' RO/DI. TDS readings are at output of RO and final output after DI. Assuming the meter is correct, at startup the final output is at 1ppm TDS. Within 10 minutes it's at zero. Since I usually make 30+ gallons at a time, I feel this is not enough to worry about.
woodnaquanut
Active member
Maybe you should take up needlepoint instead! :lol: :lol:
One of the least expensive things you can do to improve efficiency is to replace the pre filter and carbon. When I did this the PSI to the RO membrane went from 45 to 60+.
lokii_37
New member
I was talking about running dual RO membranes. I wasnt saying it would prevent TDS creep. I was saying that way you can filter the grey water the first RO membrane rejects. yes the second RO membrane will last a much shorter time but being able to utilize the grey water so it does not go to waste would be good.
It isn't so much the work, but the ATO will reduce the amount your salinity fluctuates between top offs.
Problem w/ that is it's not good for RO/DI to run 'just a little' so there would have to be a system to wait till TO was almost empty.
Oh yea, my tank is not very close to the RO/DI. I knew there was another reason!
That's why I'm getting a topoff for my topoff. I'm setting up my Apex to run my ATO, and plan on having it also run my DI for 70 minutes, 3 times per week, but will also use a float switch as a failsafe for high water level.
lokii_37
New member
I dont know what rate you get RO from your membrane but with a 75GPD membrane running it for 70 minutes will only make about 3 gallons. why not run it for 210 minutes only once a week, and therefor prolonging the life of your DI resin.
The solenoid valve I purchased states that it should only be on for a max of 2 hours. I plan on playing with the time until I get it right.
zeroinverse
New member
John:
Here is that "article" & DiY I wrote up last time. Probably it was last year.
http://www.reefcentral.com/forums/showthread.php?t=2252240
Here is that "article" & DiY I wrote up last time. Probably it was last year.
http://www.reefcentral.com/forums/showthread.php?t=2252240
woodnaquanut
Active member
Thanks Ron. I had read that thread 'way back when'.
Unfortunately, that solution won't work for me. I have an on demand hot water heater. It doesn't do well for a trickle of water. There needs to be more flow for it to kick in.
If the water needs to be 70-80 for best production, we should heat it all year. I think the tap water is colder in winter (seems like shower valve needs to be more hot in winter), but I really have no actual data.
So I just measured my tap temp. Started out at 57, went down to 51 then after running for a couple of minutes, came up to 64! With the filter outside, I'd guess there would be some chilling during the transit from house pipes to filter. I'll be running the filter today and will measure output temp.
Luckily, my wife did not see me measure tap temp. It would have been just more evidence I'm nuts!
Just so I can get membership in Grant's mad scientist club, I'll do the tests again in August! (hooray for iCal!).
At this point, I'd like to do some heating just to make sure the unit doesn't freeze. If it improves output that would be an added advantage.
Unfortunately, that solution won't work for me. I have an on demand hot water heater. It doesn't do well for a trickle of water. There needs to be more flow for it to kick in.
If the water needs to be 70-80 for best production, we should heat it all year. I think the tap water is colder in winter (seems like shower valve needs to be more hot in winter), but I really have no actual data.
So I just measured my tap temp. Started out at 57, went down to 51 then after running for a couple of minutes, came up to 64! With the filter outside, I'd guess there would be some chilling during the transit from house pipes to filter. I'll be running the filter today and will measure output temp.
Luckily, my wife did not see me measure tap temp. It would have been just more evidence I'm nuts!
Just so I can get membership in Grant's mad scientist club
, I'll do the tests again in August! (hooray for iCal!).At this point, I'd like to do some heating just to make sure the unit doesn't freeze. If it improves output that would be an added advantage.
Dapg8gt
New member
I've also read of people looping the incoming line in a bucket of heated water. For instance instead of having a short line from the supply you run 10x the tube thru a large bucket that is heated with a heater. That will raise the incoming water to whatever temp you need.
I think if you built a insulated enclosure around the unit ro tubing looped in the heated bucket you would not only heat the incoming water but you would also keep the environment that the unit is in up to temp also just with the radiant heat from the water source.
Come to think of it my garage which is semi insulated has my 55g Brute sw mixing bucket and my frag system, Prob about 150g of heated water total keeps the garage a lot warmer than it was without it. You may be able to do it that way I think it would work if your willing to pay for the electricity to heat the small volume of water..
I personally think a 20g Brute about 100' of ro tubing and a 150w heater in a insulated enclosure would work great..
I think if you built a insulated enclosure around the unit ro tubing looped in the heated bucket you would not only heat the incoming water but you would also keep the environment that the unit is in up to temp also just with the radiant heat from the water source.
Come to think of it my garage which is semi insulated has my 55g Brute sw mixing bucket and my frag system, Prob about 150g of heated water total keeps the garage a lot warmer than it was without it. You may be able to do it that way I think it would work if your willing to pay for the electricity to heat the small volume of water..
I personally think a 20g Brute about 100' of ro tubing and a 150w heater in a insulated enclosure would work great..
zeroinverse
New member
Amount of electricity you spend on the coils and electrical heater will add up much more compared to gas-powered water heater.
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