RO/DI question?

CU kills · 09/25/2007, 11:30 PM

Is a DI really needed or is RO sufficiant on its own?

Scottdl99 · 09/26/2007, 12:48 AM

I took off my DI, my TDS is higher when it is hooked up. I prefer not to run it, some ppl may argue that, but I have lower TDS without it.

jkt182 · 09/26/2007, 06:05 AM

Quote:

Originally posted by Scottdl99
I took off my DI, my TDS is higher when it is hooked up. I prefer not to run it, some ppl may argue that, but I have lower TDS without it.

This is because the media is bad in your DI. I had flushed my RO/DI (brand new) when I got it and it killed my DI media. I was running 13ppm at the canister level and then 60ppm after the DI. I switched out my media, let it run about 2 gallons and my TDS went back to 1ppm.

michaeljames · 09/26/2007, 07:09 AM

as long as you replace the DI media every six months or so depending on usage your better off with it, it's reasonably cheap to buy.

GlobaLPimP · 09/26/2007, 08:57 AM

You "can" do without it - however, I wouldn't

Just make sure you get a TDS meter with the system. If you have a TDS reading higher than "ZERO" - something's wrong and needs to be corrected.

Scottdl99 · 09/26/2007, 11:29 AM

Quote:

Originally posted by jkt182
This is because the media is bad in your DI. I had flushed my RO/DI (brand new) when I got it and it killed my DI media. I was running 13ppm at the canister level and then 60ppm after the DI. I switched out my media, let it run about 2 gallons and my TDS went back to 1ppm.

Nope sorry, it was brand new.

I don't like the DI's

CU kills · 09/26/2007, 01:06 PM

Okay so the DI should be able to be bypassed in case the TDS is high?

jkt182 · 09/26/2007, 01:22 PM

Quote:

Originally posted by CU kills
Okay so the DI should be able to be bypassed in case the TDS is high?

Different people are going to have their opinions. If you don't use the DI then you're only going to remove about 94% of the bad stuff. If you end up processing through the DI you'll remove about 99% of the bad stuff.

When you buy a new RO/DI unit you have to flush the system. This means running the system and throwing away about 10 gallons of water. By then your TDS reading after your DI should read about 1ppm. This means you've removed 99% of the bad stuff.

If you have a hard flush your DI resin might be bad, then you'll have to replace the resin. Run another few gallons through it and you'll get 1ppm. Which is what you want.

If you buy water from the LFS you'll get 1ppm water. They tend to add buffer to it as well.

It's totally up to you. Don't listen to just one person's opinion. If you can afford it, go w. the DI, if not go w. just the RO.

CU kills · 09/26/2007, 01:40 PM

No matter what it will be better than paying the $40 per water change would have to spend, with out needing to go to the store.

bertoni · 09/26/2007, 01:55 PM

If the TDS is higher after the DI phase, something's wrong with the DI. I always run both RO and DI. When the DI has a problem, I fix it.

CU kills · 09/26/2007, 06:28 PM

I will definatly get a RO/DI system with a DI bypass. That way I can test before and after the DI. Also I will be able flush the membrane with out ruining the DI resin.

09/25/2007, 11:30 PM	#1
CU kills Registered Member Join Date: Sep 2007 Location: Dayton, NV Posts: 104	RO/DI question? Is a DI really needed or is RO sufficiant on its own? __________________ Life is the only STD that is 100% fatal. Current Tank Info: 75lbs LR +or- a few LBS, 50lbs of LS, 20 Dwarf Cerith snails, 15 Nerite snails, 10 Nassarious snails, 2 Ninja star snails, 1 28+ polyp zoa colony, 1 Green Galxia, 1 Orange Cap Montipora, 1 Red Mangrove, 3 Yellow Tail Damsels, 1 True Perc Clown.

09/26/2007, 12:48 AM	#2
Scottdl99 Registered Member Join Date: Jun 2006 Location: Indy Posts: 411	I took off my DI, my TDS is higher when it is hooked up. I prefer not to run it, some ppl may argue that, but I have lower TDS without it. __________________ 80g Shallow Deep Blue: 200w LED, SWC 160, MP 10's 120g Shallow Frag Tank: 200w LED, 150w HQI's, SRO1000, WP 10's

09/26/2007, 07:09 AM	#4
michaeljames Registered Member Join Date: Mar 2007 Location: Rochester NY Posts: 737	as long as you replace the DI media every six months or so depending on usage your better off with it, it's reasonably cheap to buy. __________________ "This tastes like crap!" "Well here, try it with some selcon and garlic..." Current Tank Info: 180g RR AGA 2 x 250w SE MH 1 x 175 SE MH 2 x 6' Super atinic VHO Iwaki 100 return Reef Octopus Skimmer

09/26/2007, 08:57 AM	#5
GlobaLPimP Registered Member Join Date: Jul 2006 Location: Palm Harbor, Florida Posts: 911	You "can" do without it - however, I wouldn't Just make sure you get a TDS meter with the system. If you have a TDS reading higher than "ZERO" - something's wrong and needs to be corrected. __________________ This hobby is educational; it teaches you how to spend a lot of money in a hurry! Current Tank Info: 75gl, SPS, LPS, IceCap/T5/SLR, 2 modded Tunze 6045's, PCI 350 skimmer w/ Gen-X 2400, 95lbs LR, GEN-X 4100 return

09/26/2007, 01:06 PM	#7
CU kills Registered Member Join Date: Sep 2007 Location: Dayton, NV Posts: 104	Okay so the DI should be able to be bypassed in case the TDS is high? __________________ Life is the only STD that is 100% fatal. Current Tank Info: 75lbs LR +or- a few LBS, 50lbs of LS, 20 Dwarf Cerith snails, 15 Nerite snails, 10 Nassarious snails, 2 Ninja star snails, 1 28+ polyp zoa colony, 1 Green Galxia, 1 Orange Cap Montipora, 1 Red Mangrove, 3 Yellow Tail Damsels, 1 True Perc Clown.

09/26/2007, 01:40 PM	#9
CU kills Registered Member Join Date: Sep 2007 Location: Dayton, NV Posts: 104	No matter what it will be better than paying the $40 per water change would have to spend, with out needing to go to the store. __________________ Life is the only STD that is 100% fatal. Current Tank Info: 75lbs LR +or- a few LBS, 50lbs of LS, 20 Dwarf Cerith snails, 15 Nerite snails, 10 Nassarious snails, 2 Ninja star snails, 1 28+ polyp zoa colony, 1 Green Galxia, 1 Orange Cap Montipora, 1 Red Mangrove, 3 Yellow Tail Damsels, 1 True Perc Clown.

09/26/2007, 01:55 PM	#10
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	If the TDS is higher after the DI phase, something's wrong with the DI. I always run both RO and DI. When the DI has a problem, I fix it. __________________ Jonathan Bertoni

09/26/2007, 06:28 PM	#11
CU kills Registered Member Join Date: Sep 2007 Location: Dayton, NV Posts: 104	I will definatly get a RO/DI system with a DI bypass. That way I can test before and after the DI. Also I will be able flush the membrane with out ruining the DI resin. __________________ Life is the only STD that is 100% fatal. Current Tank Info: 75lbs LR +or- a few LBS, 50lbs of LS, 20 Dwarf Cerith snails, 15 Nerite snails, 10 Nassarious snails, 2 Ninja star snails, 1 28+ polyp zoa colony, 1 Green Galxia, 1 Orange Cap Montipora, 1 Red Mangrove, 3 Yellow Tail Damsels, 1 True Perc Clown.