source water very high alkalinity

BigJay

Well-Known Member
Well I just test my 90g and its off the charts alkalinity wise and calcium is around 380. So I did a 15% water change and alkalinity actually went up. So I mixed up another batch of reef crystals and alkalinity was around 7 meq/l so I figured it was bad salt then I decided to test my RO water and its around 5.5 meq/l . Any ideas on why or what I could do?

Its well water with white mineral softner coming into the house and a 3 stage RO.
 

BigJay

Well-Known Member
just did some reading am I to assume the RO membrane needs replacing? I've tested for phosphates and nitrates from my RO and they are at 0.
 

fatman

Has been struck by the ban stick
I would agree, sounds like a bad RO membrane.

It is recommended that all water that has a calcium hardness of over 200 or 250 be run through a water softener before run through a RO filter. A RO membrane has a short life span with hard water. I do not understand what you mean by white mineral softener. Are you referring to a water softener that uses salt.

It is a good idea to get a TDS (Total Dissolved Solids) meter to use to test a RO waters output. The water should be tested straight from a tap and then from the RO filter discharge. If the filter is not removing at least 95 percent it is inadequate as a stand alone filter and sjhould be followed by an DI filter. If the output drops below around a 90 percent TDS removal the filter membrane should be replaced. A TDS meter can be had for around $25 to $30 plus postage.
 

BigJay

Well-Known Member
Thanks. I think I am going to order a 4 stage RO/DI unit. My membrane alone is like $70 and I just was reading and its output is only 14 g per day. I have been getting almost twice that meaning a good chance the membrane is ruptured. Kind of sucks though since I still have one pre-filter and carbon filter left for the unit.
 

fatman

Has been struck by the ban stick
Thanks. I think I am going to order a 4 stage RO/DI unit. My membrane alone is like $70 and I just was reading and its output is only 14 g per day. I have been getting almost twice that meaning a good chance the membrane is ruptured. Kind of sucks though since I still have one pre-filter and carbon filter left for the unit.

Your unused pre filter and carbon filter can stll be used. If they are for the same size housing just use them in the new filter housings. If they are a different size just keep the old filter housing and install them inline and you will be able to use either one or the other or both sets. If they were inline filters then it is no great loss. They are of very low capacity and are usually installed inproperly by the manafacturerers anyway. A RO membrane can be installed horizontal or vertical but prefilters, carbon and DI filters should always be installed vertically. This is especially important with GAC and DI filters. This vertical palcement is so as to prevent channeling.
 

BigJay

Well-Known Member
they are the micro line filters and way overpriced IMO. Without the a whole lot of space saving. My well guy is on his way her now with a 50 GPD unit for me (wholesale of course :) ) and a second pressure tank made out of plastic. We are gonna plumb the new RO unit in place of the old and split off a line going to a DI unit then to the plastic tank under the tank. I am probably not going to do an auto top off at the moment but at least topping off will just be pressing the button.
Thanks for the quick feed back. I grabbed 20 gallons out of his 500 gallon RO tank and it tested at 3.5 meq/l alkalinity and he lives pretty close so I expect to see a significant drop in alakalinity.
 

BigJay

Well-Known Member
holy crap.. My well guy just left and put a TDS meter on my source water 776.. then my Microline RO 776... then my tank guess what 776. My RO membrane was completely non-functioning. Goes to prove I guess the phosphate and nitrate test on source water does you no good. Looks like I am going to be doing a butt load of water changes soon as I get the units switched out.
 

Boomer

Reef Sanctuary's Mr. Wizard
Great post and advice FM thanks :) I think 776 ppm TDS is the highest I've seen posted

Jay if you want a good system and don't want to get ripped off for cost go here.

The Filter Guys
 

fatman

Has been struck by the ban stick
Micro line filters are convenient in that they are a tad bit easier and less messy when changing out the prefilter and carbon filters. You give up quite a bit in capacity and performance though.

Please remember also that RO membrane removes more and does it most efficiently when run for longer periods of time rather than short periods of time. One of the problems of having pressure tanks and float valves controlling the RO filter is that the filters are very often only running for only a few minutes at a time and therefore put out water of a higher TDS. This puts a higher load on a DI filter, which has limited a limited capacity. If using mixed bed resins in a DI filter they are not rechargeable so they would have a very short life span.

Any time you run your RO filter you should try to run at least several gallons of water especially if you have a water source with a high TDS. Your water definitely fits the bill for a high TDS source. Sort of like Arizona desert water.
 

Boomer

Reef Sanctuary's Mr. Wizard
Jay on another note do you have a water softener, as that would help allot.
To add to FM, with the info you posted so far, you are also going to have high CO2, which will go right through the RO and kill your DI in short time. You may need to make a DIY CO2 degasser post RO and pre-DI. Also, what is the line pressure to the RO and water temperature.
 

BigJay

Well-Known Member
I'm not sure on pressure but temps can range from anywhere from 70 to 100 degrees depending on outside temp(the first run can be upwards of 120 till the attic lines clear). Off the top of my head I think we set the pressure switch at somewhere around 65 but I could be way off, I'll have to ask the well guy.
Its well water and there is a softener.
I just installed the new 4 stage unit from my well guy and I am putting a branch circuit to a two stage add on DI under in the tank stand.
Another interesting fact is one of the in side ferrules to one of the tubes was copper from the main water supply. Normally not a big deal if my RO is working but since the membrane was shot it might have built up to disaster.
Thanks for the tip on the degasser I'll look into it right now.
 

BigJay

Well-Known Member
btw I tested the new RO water for alkalinity and its at less then 2 meq/L what a difference. I am gonna try to grab the TDS meter tommorrow and see what I am now.
 

BigJay

Well-Known Member
I should note I started dosing the tank with calcium chloride today. Raised calcium 20 ppm and decreased alkalinity by 1 meq/L. Gonna try dosing it every day for the next week with water changes and see if I can't get the alkalinity back within reason.
 

fatman

Has been struck by the ban stick
Jay on another note do you have a water softener, as that would help allot.
To add to FM, with the info you posted so far, you are also going to have high CO2, which will go right through the RO and kill your DI in short time. You may need to make a DIY CO2 degasser post RO and pre-DI. Also, what is the line pressure to the RO and water temperature.

>OK<, I bite. How does one make an inline DIY CO2 degasser. I can picture an aeration chamber but that would not be inline. :doh: But you did not say inlne. I am just hoping, I guess. Are you talking about just vesseling the water aerating it and then pumping it through a DI into another vessel?

About how high do your carbonates have start out as to be generally before CO2 becomes an issue. My water is lime softened by the water treatment plant to a hardness of less than 100.

I pretreat my water by first running it through a full sized house hold water softener and then an equally sized GAC filter. I have never thought to test my water for CO2 prior to the DI filter as I have only read a small amount of material on this issue. Nothing in the way of an article specifically dealing with this issue.

You probably know what lime softening is, but others might not.

It is basically just adding a lot of calcium (lime CaO) to water and thereby creating a calcium hydroxide slurry which is then added to the water being treated. This neutralizes the carbonic acid and then raises the pH to about 10.3 to bring about precipitation of calcium carbonate by converting all bicarbonate to carbonate. They then add more lime (calcium hydroxide slurry) to bring the pH up to about 11 (actually they perform the two additions of calcium hydroxide at the same time) to remove carbonate hardness due to Magnesium. And finally, to remove non carbonate hardness, they add soda ash. They also might even add additional sodium hydroxide followed by additional soda ash to remove non carbonate hardness due to Magnesium.

(Makes one thirsty Huh!).:nekid:
 

Boomer

Reef Sanctuary's Mr. Wizard
Ok and I take it then that some of the water from the water softener goes to the RO I hope ? And not from the well to the RO, a no- no in your case. OK temp. RO's work better at higher temps, not to high though and at higher line pressure.

When you are all set up measure the pH , Alk and TDS of the RO water. Go to this calculator and type in the pH and Alk, which will give CO2


Measuring CO2 levels in a Planted Tank

Take the sum of the CO2 ppm + TDS ppm and then divide the CO2 ppm by the sum = % of the DI that CO2 alone will deplete the DI.


Example:
Alk 1.5 meq / l and pH 7.2

1.5 meq / l x 2.8 = 4.2 dKH

Plugging into the Calculator 4.2 dKH and pH 7.2 = 7.95 ppm CO2

RO-TDS = 15ppm

15 ppm TDS + 7.95 ppm CO2 = 22.95 sum

7.95 sum / 22.95 ppm CO2 = .346 or ~ 35 % of the DI will be depleted by just the CO2 alone.


How does this happen ? The Anion part of the DI is OH- and the CO2 will react with it or the water.

OH- + CO2 or CO2 + H2O = HCO3- now being stuck on the anion exchange resin, depelting the OH- on the DI resin = depleting the DI resin.
 
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Boomer

Reef Sanctuary's Mr. Wizard
FM

Are you talking about just vesseling the water aerating it and then pumping it through a DI into another vessel?

Yes / say but you do not have to have a pump if you gravity feed it from the Degassing unit to the DI.

You probably know what lime softening is, but others might not.

Yes, but that is a pain for most to do.


Now if you have lots of money then :lol:

Liqui-Cel EDI CO2 Remover
Liqui-Cel: Degassing Liquids, Deaeration of Liquids, Forced Draft Deaerator

Here is the only cheap DIY Degasser I can find. We have been working on a better one but have not gotten around to doing it yet :(
 

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Boomer

Reef Sanctuary's Mr. Wizard
Note:

This DIY can get tricky as you need to keep the water above the drain line. If the water line gets to the drain line it will suck in all that CO2 laden air. And if you have the Degased water go to a container then it needs to be pertty air tight. You do not want ambient air mixing in with the Degassed water as it will just pull in CO2 from the air.
 
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