RODI Water Question

[docshipwreck]

Hello All,

 

I've been struggling with GHA for the last few months. My tank is 11 months old. I thought perhaps my RODI filters or pre filters needed changed. I bought a TDS meter after changing light settings, feeding less, trying GFO.

 

I have an RO Buddie. I depleted the DI cartridge from them an replaced it was another brand. This has been the only major change. I haven't tracked gallonage through it but carbon/sediment filters should be changed every 6 months and I've ordered those.

 

Currently faucet TDS is 389 +/-. Current DI output it between 7-9. Could this low level of TDS be responsible for my algae? I am going to replace the carbon and sediment and see what the TDS is after the change.

 

Any thoughts?

[Tamberav]

Yes, should be zero. The RO buddy is not a powerhouse but can work for people with lower TDS tap but yours is pretty high so not sure what to expect out of this small unit. If the cartridges are depleting faster than expected, chlorine will get through which will ruin the membrane. A chlorine test kit would be the way to tell.

 

How long has it been since the carbon/sediment was changed?

[docshipwreck]

11 hours ago, Tamberav said:

Yes, should be zero. The RO buddy is not a powerhouse but can work for people with lower TDS tap but yours is pretty high so not sure what to expect out of this small unit. If the cartridges are depleting faster than expected, chlorine will get through which will ruin the membrane. A chlorine test kit would be the way to tell.

 

How long has it been since the carbon/sediment was changed?

Do you recommend a specific test? The carbon and sediment are original to unit and I purchased that approximately march

[Tamberav]

I use

 

 https://www.marinedepot.com/SpectraPure_Chlorine_Test_Kit_With_10_Tablets_Specialty_Test_Kits_for_Saltwater_Aquariums-SpectraPure-SP5553-FITKSI-vi.html

 

If there is chlorine in your waste water than it is getting to your membrane and your carbon needs to be changed. You can use this kit to get an idea how fast your carbon exhausts and then know exactly how many months to change the filter without having to keep testing. 

 

If a new carbon block does not fix the issue... I would guess the unit is not powerful enough for the water in the area... I am assuming since they are non standard carbon sizes you can't simply buy a better quality carbon block. 

 

 

If you have well water than chlorine isn't an issue obviously.

 

Sediment blocks are replaced when there is a significant drop in pressure or every 6 months depending on use. 

[Tamberav]

BTW I would be curious what the TDS is before the DI stage

[Clown79]

Is your water treated with chlorine or chloramines?

If chloramines you need special carbon blocks with catalytic carbon and you need 5 stages on the rodi.

[Exodus]

IMO 7~9 TDS is extremely low and I would look elsewhere for whats "feeding" the GHA. What are your Phosphate Levels, and just how long is your lights on daily? What filtration are you using to extract excess nutrients? I had tanks for many years before ever touching an RODI filter using just tap water which locally happens to be ~25 TDS without very many Algae issues. 

[Tamberav]

7 to 9 is low but we don't know what is in that 7 to 9 without a test. My concern is you pay for a RODI and it is not working properly or removing chlorine properly then it will ruin the membrane and the TDS is going to only increase as the membrane goes to hell and exaust the DI stage quickly. 

 

We have chloramine and I only use a quality carbon filter and chloramine has not been detectable but we don't have it in the quantity that some places do. 

[Clown79]

Chloramines aren't removed with standard carbon blocks. 

 

[Tamberav]

21 minutes ago, Clown79 said:

Chloramines aren't removed with standard carbon blocks. 

 

 

 

Edit: Nevermind, on their website it says: "0.5 micron Carbon Block Pre-Filter with 20,000 ppm-gallons chlorine removal capacity"

 

They just call it a 0.5 micron carbon block but it does remove chlorine/chloramine. I tested the water going in and coming out directly after and definitely went from bright pink to clear... no problem.

 

https://www.marinedepot.com/0.5_Micron_Carbon_Block_Replacement_Filter_for_Marine_Depot_SpectraPure_Kent_Marine_Carbon_Block_Filter-Marine_Depot-RO1131-FIRORPCB-vi.html

 

This is why standard filter sizes rule, can just change it up if something isn't working for your set up.