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Should I replace my DI filters

Mr. Fishy Fish

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Hey everyone, I have an old MPDI-90 Spectrapure unit with a Madcap Add-On. I haven't used this thing for several years, so I let it run and noticed that the gauge was staying at 0 kPa. I'm assuming my sediment filter is clogged, or the gauge is broken. The sediment filter is dirty so that could be the reason the gauge is reading zero. After I let it run for approximately 15 minutes, then I put some processed water into a cup to test it with my handheld TDS meter and the results were 3 ppm. So what do you guys think I should do to get it to zero? I already ordered a new sediment/carbon filter. Do you guys think I should get a new Silicabuster Di Cartridge and MaxCap Super DI cartridge? Also, do the cartridges specifically have to be from spectrapure? or can I use any replacement DI? Please let me know if you guys need more information.

Note: I have never replaced anything on this RO/DI unit in my life. My tap water tested at 116 ppm
 
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Mr. Fishy Fish

Mr. Fishy Fish

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Okay, I just looked and spectrapure filters are going to cost me around 300 dollars in Canada. That's way too much. I'm just going to buy a new RO/DI instead for the same price. Do any of you know if the AquaFX Barracuda Mako is any good?

Edit: I meant to say DI filters or w.e they're called
 
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Mr. Fishy Fish

Mr. Fishy Fish

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Okay, I just looked and spectrapure filters are going to cost me around 300 dollars in Canada. That's way too much. I'm just going to buy a new RO/DI instead for the same price. Do any of you know if the AquaFX Barracuda Mako is any good?

Edit: I meant to say DI filters or w.e they're called
I may have jumped the gun there. I found some for much cheaper. Thanks for the help everyone.
 
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Mr. Fishy Fish

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So typically the third canister on the bottom (after carbon and sediment as well as after DI) you put mixed bed DI resin (color changing is best.
I was going to go for the colour changing sediment, but in Canada it costs 120 + tax. So I got the other one instead. I just hope they get here before the tank does.
 
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Mr. Fishy Fish

Mr. Fishy Fish

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Are changing the whole canister or just the resin inside?
Here a place in Canada that sells resin for the 10 filters. 20$

https://www.reefsupplies.ca/online-...g-Bulk-DI-Resin-1.4-lbs-1-x-10-Cartridge.html
So I can just get resin and refill the canisters? I wish I knew that before I placed the order. Oh well, I guess I'll have backup canisters. Can I use the same resin for the MaxCap? I'm not sure what the difference is between the Maxcap DI and the other DI (third canister)
 

Opus

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So I can just get resin and refill the canisters? I wish I knew that before I placed the order. Oh well, I guess I'll have backup canisters. Can I use the same resin for the MaxCap? I'm not sure what the difference is between the Maxcap DI and the other DI (third canister)
The maxcap is just the way they fill the cartridge. If you notice, it is 2 different colors instead of the entire thing being one color. They have different resins in the top and bottom. Most people just run a mixed bed resin in the entire thing. The link Biglew11 gave you will work. If you want to save a little more money, you can get the mixed bed resin that doesn't change color. It is a convenience factor you pay for and I personally find it really doesn't help me much. Once it changes color I still get 0 tds out of mine for several more months. Unless you are trying to filter out something specific, I don't think you need 2 different DI canisters.

You say you haven't used the unit for several years. Did you leave water in the ro membrane cartridge? If not, then it is probably shot. You said your tds reading was 3, but was that after the di or after the ro membrane? With your 116 tds at the tap, I would expect your tds after the ro membrane to be 2 or maybe 3.
 
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Mr. Fishy Fish

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The maxcap is just the way they fill the cartridge. If you notice, it is 2 different colors instead of the entire thing being one color. They have different resins in the top and bottom. Most people just run a mixed bed resin in the entire thing. The link Biglew11 gave you will work. If you want to save a little more money, you can get the mixed bed resin that doesn't change color. It is a convenience factor you pay for and I personally find it really doesn't help me much. Once it changes color I still get 0 tds out of mine for several more months. Unless you are trying to filter out something specific, I don't think you need 2 different DI canisters.
Yeah, I figured the color indicating feature wasn't that big of a deal. Also, I thought the MaxCap's purpose was to extend the time of the DI, not for filtering specific particles out. At least that's how the MaxCap was advertised. Either way I might as well keep it, especially if I can buy the resin at that price.

You say you haven't used the unit for several years. Did you leave water in the ro membrane cartridge? If not, then it is probably shot. You said your tds reading was 3, but was that after the di or after the ro membrane? With your 116 tds at the tap, I would expect your tds after the ro membrane to be 2 or maybe 3.
Luckily without realizing it I did leave water in it. The whole thing was filled with water, so I'm assuming the RO membrane was also filled with water.

You said your tds reading was 3, but was that after the di or after the ro membrane? With your 116 tds at the tap, I would expect your tds after the ro membrane to be 2 or maybe 3.
There is a yellow tube that comes out of the membrane, and I did not test that water. I'm assuming that's the RO water. I tested the water coming out of the blue tube that is attached to a DI cartridge.
 

K7BMG

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I am a pure water freak.
If my RO/DI sat for several years wet or not.
I would replace all the disposables consumables.
Membranes, Resins, sediment and carbon.

To much to risk for a few bucks.
 
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Mr. Fishy Fish

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I am a pure water freak.
If my RO/DI sat for several years wet or not.
I would replace all the disposables consumables.
Membranes, Resins, sediment and carbon.

To much to risk for a few bucks.
You're totally right, I'm being cheap because I already spent a fortune on everything else. But that makes no sense, why the hell would I cheap out on my water... Which membrane would I need though?
 

K7BMG

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I would hope the unit would have a manual or the old membrane should have a lable.
 

Opus

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You're totally right, I'm being cheap because I already spent a fortune on everything else. But that makes no sense, why the hell would I cheap out on my water... Which membrane would I need though?
Your unit came with a 90gpd membrane so I would stick with that unless you want to mess with changing the flow restrictor. If you want to stick with spectrapure, you have 2 choices if you order from reefsupplies.ca. The 99% or 98% rejection rate membrane. Based on your tap of 116 tds, you are looking at either a 1 or 2 tds after the ro membrane if the membrane works as advertised. A typical di cartridge will make 4400 gallons of 0 tds water with 1 tds water going into it. You will get 2200 gallons if 2 tds water is going into it. It is up to you to decide if the $28 difference between the 2 membranes is worth it. If you take care of the ro membrane by changing out the sediment and carbon filters when needed, the ro membrane should last 5 to 7+ years unless you are making a ton of water.
 
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Mr. Fishy Fish

Mr. Fishy Fish

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Your unit came with a 90gpd membrane so I would stick with that unless you want to mess with changing the flow restrictor. If you want to stick with spectrapure, you have 2 choices if you order from reefsupplies.ca. The 99% or 98% rejection rate membrane. Based on your tap of 116 tds, you are looking at either a 1 or 2 tds after the ro membrane if the membrane works as advertised. A typical di cartridge will make 4400 gallons of 0 tds water with 1 tds water going into it. You will get 2200 gallons if 2 tds water is going into it. It is up to you to decide if the $28 difference between the 2 membranes is worth it. If you take care of the ro membrane by changing out the sediment and carbon filters when needed, the ro membrane should last 5 to 7+ years unless you are making a ton of water.
I purchased the 99% membrane and a new gauge. The water faucet in my basement is an irrigation faucet, when I tested the RO/DI unit I had the faucet knob opened to the max point. I'm sure that affected my TDS since there was probably too much water flowing in at once.
 

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