Changing GFO & Carbon Media

[sdavi66572]

Been running my dual gfo carbon reactor about 2 weeks. Starting to get some more green hair algae. Phosphates are about .38. Should I be changing the gfomedia out and what about the carbon media??

 

[oh207]

It is recommended to start off slow with gfo and gradually increase the amount. You don't want to quickly strip the tank. In your case it probably means the hair algae is out-competing the gfo.
Gfo will last longer than the carbon.
Best practice is to put carbon in the first reactor and gfo in the second.
I then change carbon every 3 weeks and gfo every 6 weeks.
This way if the carbon gets clogged, (and it usually does) its more economical to replace frequently.

 

[sdavi66572]

I used brs calculator for gfo and carbon to get correct amounts. For GFO it was 3 1/2 cups media. So I started with 1 3/4 cups. And for carbon it was 1 1/2 cups so I started with 3/4 cup. This is for my 240 gallon.
I purchased BRS dual GFO & Carbon reactor. I am running GFO in first chamber and carbon in second chamber

 

[oh207]

How does the GFO flow looks, is it still tumbling? Also, I think its best to place the GFO in second chamber. Better to replace the carbon more frequently (due to clogging from detritus), than to replace GFO.
I didn't realized your system was 240g. I only have experience with a 65g and a 120g and I used 2 cups of each! Maybe someone else with similar system can offer feedback.

 

[sdavi66572]

GFO is still tumbling. I try and keep a close eye on it.

 

[Trex]

What is your source water? Tap or RO/DI ? (( If RO/DI, what is the TDS? ))

.38 is actually very high for phosphates. Going to have a hard time bring it down with just GFO.

 

[sdavi66572]

I have been using culigans reverse osmosis water. I have never checked the TDS. Before I started using my brs dual gfo carbon reactor my phosphates were about 1 two weeks ago.

 

[sdavi66572]

TDS is 35ppm

 

[Trex]

That is pretty darn high.

When is the last time you changed the filters?

At this point, I would change all of them --- Prefilter, Carbon, RO membrane* and DI resin.

What is your tap water's TDS?

* I would get the DOW filmTEC 75 GPD membrane, has a 98% rejection rate, which will make your DI resin last longer. Might have to change the flow resistor to match the GPD.

 

[sdavi66572]

Tap waters TDS is 327.
Still thinking changing all my filters is the thing to do?

 

[Trex]

Most likely yes, all of them. At best, your RO membrane is still good, but given the numbers, I would be surprised. And even if it was still good, you are only getting 90% rejection rate. Given your somewhat high (( My tap is 150-160 )) you will go through your DI resin quicker. Would get the DOW membrane I mentioned above, will extend the life of your DI resin.

If possible, test the TDS of just the RO -- before the DI resin, would give an idea of the rejection rate of your membrane.