TDS levels Please respond.

[seafan]

I have an RO unit (I was told by my local fish store DI is overkill in miami beach) My TDS is between 23-37 I was wondering if this is okay.


Also I was wondering what is your TDS #.

 

[ellisz]

That is not bad but my TDS after the DI is 0-1. Some people use water with a higher TDS than that and do ok though.

 

[seafan]

The reason he gave for not using DI is because he said that it makes keeping calcium/alkalinity high, I read something that says that if you clean out all the dissolved solids the water will become acidic in a short while, is this true?

 

[seafan]

BUMP!!!

 

[seaham358]

TDS is total disolved solids, is the TDS you show good or bad?? no way to know with out having the water anilized in a lab. Do you have a algae issue? If not then you may do fine without a DI unit. Have you tested for nitrates and phosphates in your top off water? If you have any then you need a DI.
I am not sure about the acidic question...
You may need to use more addidtves to keep up your alk and cal with a ro/di unit. Some of us have no choice.. If I don't us a ro/di then I have cyno bacteria issues because I have PO4 in my tap water.. For the little extra cost of a Di cartridge IMO its worth using one.
I have used ro/di for 3 years now and think it is great stuff.

 

[ellisz]

I have never heard of just recommending RO water over RO/DI. I have heard of some DI units(I think that is what they are) that produce clean water without the waste of the RO units have. Anthony Calfo talked about these at a recent conference. Was not sure on the exact unit though.

I use RO/DI water and don't add anything to my water currently. I recently got some Aragamilk that I have been adding to my top off water in place of kalk but I have been out of kalk for 6+ months. I use Oceanic salt and it keeps my levels at 420 Ca and 2.5-3 meg/L alk. I have not tested since using the Aragamilk though.

 

[seafan]

I have never heard of just recommending RO water over RO/DI

He said that DI units burnout quickly and might not be worth the investment, he did not recommend one over the other. I had already bought the unit beforehand and was asking if it was necessary to buy a completely different unit.

Now here's the question: Can I buy just a DI cartridge w/o a whole unit?

 

[MT79]

Can I buy just a DI cartridge w/o a whole unit?

Do you mean an add on DI unit? If so here is the one I used- http://www.buckeyefieldsupply.com/showproducts.asp?Category=39&Sub=104
They also sell DI replacement media/refillable cartridges. HTH

 

[greenmaji]

RO/DI water would only appear to acidify.. it would be the small amount of CO2 from the CO2 in the air from the room that would be in it that would make it read a lower then nurtural PH. The same would hold true with RO water. A TDS of 37 seems to be a fairly low number to me.. (going to FW roots here LOL) Discus breeders use up to 200 TDS for spawning purposes so under 50 would seem to be pretty soft to me..
PO4 and NO3 are most likely the bigger concerns.. And the DI going bad quickly seems to be bit of a misnomer, depending on how much you use(how big your DI chamber is) it can last 6 months or more..
Ive also seen the DI only products.. they seem to use a bigger DI chamber with the same prefilters that a RO or RO/DI would come with..

 

[ellisz]

An add on DI filter should available most any place that sells RO units.

 

[seaham358]

DI unit burning out quick is something that can he can not make a general statement about.
It all depends on your water... I burn through DI quicker then some other guys i know in my reef club, others go through more then me..
My friend has used the samd DI for over a year now with 0-1 TDS. When using 1 Di I was going through about 1 cartridge every 200 gallons of water made. I run dual Di now and they last a lot longer...
Bottom line is, is your water quality good in the tank? Low nitrate, No phosphates and no nusinance algaes... If these are all good then using a DI may not be needed for you.

 

[seafan]

Ok so I went to my LFS and got the water tested, My phosphate is way too high at ~2, and my nitrate is fine. So I ordered a DI chamber and cartridge and will buy RO/DI water from the LFS in the meantime.
P.S thank you mts79 for the link.

 

[MT79]

P.S thank you mts79 for the link.

No problem. Buckeyefieldsupply has been nothing but a pleasure to deal with.

My phosphate is way too high at ~2,

2, as in 2.0 Meg/l? If so I'm assuming that is tank water (not your fresh RO/SW)...? If not you may very well need 2 DI units to remove it all if that is coming from your tap. FWIW .03meg/l PO4 is considered high/problematic. Best of luck

 

[seafan]

Sorry, it was a false return, got it checked at the LFS. It is high but not that high (~0.05).