Should i Add a 5th Stage To my RO/DI Unit

[Civicdemon]

So i keep having this issue with light brown algea on my sand, its really light but it bugs me. Only thing i have is about 3ppm nitrates and everything els is great. I think my flow is good. i read somewhere that it can be caused by the cheap lights ( Since im running PC lights. Im switching over to LED hopefully with in this month. If this problem continues then the only other thing i can think about is my water. Going into my RO/DI unit it read 175 tds comming out of my DI cartrige it reads 5 tds, its ben like this since the beggining when the cartriges where new. My only thing is Should i add a 5th stage ???? and if so what should it be ?? another DI cartrige or maybe another prefilter ???

Let me know what you guys thing. i was looking at

SpectraPure® MaxCap 1-Stage Add-on Assembly System

and thinking of getting it but not sure.

 

[Ted]

I wouldnt worry to much about 5 tds...I forget are you running a refugium?

 

[Civicdemon]

Yes running a Refugium with Live rock and Chaeto and Halimeda, Growing good. i turn the chaeto every 3 days or so. Also running a Bio Pellet reactor and a Phosfate reactor. Just recently added more Biopellets since i originally started with only a 50gl tank worth. Also added to more bags of chemi pure elite 2 weeks ago.

All readings are great. Just nitrates at 3ppm but thats not alot so im thinking its my cheap lights, or water.

i dont think its flow couse i have 2 power heads in the tank ratted at 1200 gph and my return should be at around 600 to 640 with the head pressure.

 

[Ted]

I agree must be the light...

 

[d2mini]

WOW!
If you were to test my tap water, you would get GH and KH readings that are literally off the chart. But before my DI, TDS is down to around 5 and it's zero after. Why is yours so high before the DI? You sure you don't need to change your sediment filter and carbon blocks?

 

[Civicdemon]

Im actually not sure what it is before di. Yhe before reading is before going into the unit it self so straight out the foset. Afyer everything including di its at 5. Should i test after ro membrane then after di. Or after pree filters the ro membrain the di ???

 

[d2mini]

Oh ok that makes more sense. :)
I have a tds meter hooked up to the RO/DI that takes readings before and after the DI.

Again, have you had your filters for a while? Obviously they degrade over time and the dirtier the source water the quicker they degrade. Figured it was worth asking. I would think you would be able to get zero after the DI unless your water is just really horrid. My DI is toast after just a few months and water production starts really slowing down from the filters getting clogged.

 

[Northstar24]

So i keep having this issue with light brown algea on my sand, its really light but it bugs me. Only thing i have is about 3ppm nitrates and everything els is great. I think my flow is good. i read somewhere that it can be caused by the cheap lights ( Since im running PC lights. Im switching over to LED hopefully with in this month. If this problem continues then the only other thing i can think about is my water. Going into my RO/DI unit it read 175 tds comming out of my DI cartrige it reads 5 tds, its ben like this since the beggining when the cartriges where new. My only thing is Should i add a 5th stage ???? and if so what should it be ?? another DI cartrige or maybe another prefilter ???

Let me know what you guys thing. i was looking at

SpectraPure® MaxCap 1-Stage Add-on Assembly System

and thinking of getting it but not sure.

Its not 'cheap' lights that cause algae issues, its old bulbs. If you replace your bulbs with a quality bulb this is not an issue. This is caused by 'phase shift' as incandescent bulbs age, the spectral output of the light they produce shifts to the red end of the spectrum, which is what nuisance algae loves. Changing over to LED's wont solve the issue if your main tank is reading nitrates. If you have nuisance algae and are reading 3 ppm nitrates, in reality, your nitrates are going to be a lot higher, they are just bound up in the algae

 

[BL1]

Just on a side note not related to your filter ... You know the halimeda uses calcium to grow, taking that out of your water column

 

[Civicdemon]

BL1 Actually i did not know that. Its getting pretty big also might trim it down a bit. as far as my calcium in still in the good range at 450 so im not worried on that. It still help clean the water of other stuff do right ???

As far as my lights go im changing them soon and i dont think its from them being old couse i have had this problem from the get go. Its not a huge deal but it just bothers me. its really fine. Ill see if i can get a video of the problem.

Now as far as how old are my RODI filters i would say maybe 6 months. but it still reading 5tds after di just like in the begining when i first replaced them.

 

[Civicdemon]

Needed.some top off water so.decided to test after ro. And after di. Well after the ro membrain im at 30. Then after di im at 5.

 

[d2mini]

Ok, and you mentioned adding another stage. What do you have now?
You typically have the RO Membrane, the Sediment Filter and then two Carbon Blocks. The DI makes the 5th stage. Are you looking to add a second DI?

The only other question I can think of is to ask what filters you are using? I get mine from thefilterguys.

In the end 5 tds isn't bad. Just trying to see if we can get you to zero.

 

[bjohanson1234]

How old is your RO filter?

Did you calibrate the TDS meter?

What is the rejection rate of your membrane?

To me, it seems that the RO membrane is not working right. For example, my test going into the unit is 120ish. Out the RO is usually around 4-8. After the DI, 0-1.

 

[Civicdemon]

the filters them selves are maybe 6 months now, So it might be time to change them up but my thing is there still reading the same as when i first got them. I Got the TDS metter and calibrated it when i first got it and havent done so since.

Going in to the unit im at 170 tds and out ro im at 30 and out di im at 5.

I got my filters from Marinedepot. i have the 75gpd RO Membrain, one sediments Filter, one Carbon Block filter, and one DI filter. was thinking of adint ither another sediment or DI. That way its simple to add just add it before everything or after.

What do you guys think. Ofcourse when i get the additional filter i would change all the cartriges in my existing ones.