Verifying Test Parameters

[OneFishTwoFish]

So I guess I'm becoming a Reef Nerd. My tank is just about 10 months old. I've been testing and collecting data every week for the past 6 months. Back in October 2014, I sent a water sample to AWT to establish an accurate baseline for what's in my tank, and to determine if I was getting useful results from my own testing. That's when I began collecting weekly test results. Last week, I sent another sample to AWT. There were no surprises in their results which matched mine pretty closely.

My 120 Gallon tank (approx 140 gal in the system) has fish and soft corals - no sticks yet, although I have some LPS (Bubble Coral, Goniopora, Galaxea, Torch). 120 Pounds of rock. Weekly water change of 14 Gal (10%). Skimmer pulls out some pretty nasty gunk. Two large filter socks (Eshopps 4.5" x 7" x 14") get changed weekly.

PARAMETER 10/2014 4/2015

• Ammonia mg/L 0 0
• Nitrite mg/L .0006 .015
• Nitrate mg/L 1.2 1.2
• Phosphate mg/L .03 .14
• Silica mg/L 1.2 1.2
• Potassium mg/L 363 230
• Magnesium mg/L 1400 1480
• Calcium mg/L 370 400
• Alkalinity meq/L 3.2 3
• Spec Gravity 1.026 1.025

My interpretation (with 10 months of experience, I'm NO expert):

• Phosphates have increased almost 5-fold - something should be done.
• Silica has always been high, but it is stable.
• Potassium might be a bit low.
• Magnesium might be a bit high.

Additional Notes:

• I've used Red Sea Coral Pro Salt since the beginning
• I've never dosed anything
• I've never 'run' anything (Like GFO, Carbon, Chemi-Pure, etc.)

Where should I go from here ? Is it time to begin use of something (GFO, Phosban, RowaPhos) to deal with my increasing Phosphates ? Any other hints / suggestions ?

Thanks for reading this ! I know it was loooong . . . . .

---Frank

 

[DaveK]

The key question here is how is your livestock doing? If it's doing good, go slowly and carefully with any changes.

The only issue I see is the phosphate level. You can reduce that via water changes or by using GFO.

Silica might be improved by using RO/DI water, and using a high silicate rejection RO membrane. Also check that your DI filter is working correctly. They do get used up,

I wouldn't worry too much about magnesium. You can fix that via water changes. Test your newly mixed SW to make sure the problem isn't there.

 

[OneFishTwoFish]

Thanks Dave, I appreciate your input. My livestock is doing very well - no problems. I will be very cautious with any changes. I'll test my next batch of SW. I'm getting 0 TDS out of my RO/DI, but I will investigate the 'high silicate rejection membrane'. Increasing frequency / quantity of my water changes is what I'll begin with.


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[Pat24601]

I find this pretty cool. I keep an excel spreadsheet with my parameters. I've thought of sending to AWT before. I just can't cost justify it since I don't think my water parameters are really that concerning one way or another. I've thought of doing it anyway, though.

 

[OneFishTwoFish]

Pat - I've got my test results in excel too. My initial interest in AWT was to confirm that I was getting accurate results in my own testing. I had my tank for 3 months and wanted to start adding corals. But, I thought, "what if I'm all wrong about testing ?" AWT was a reassurance that my results were ok. I'll probably do another AWT sample in 6-8 months, just to keep my sanity.


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[sirrealism]

I want to say your doing a fine job. Nice to see someone so on top of there system and its parameters. Dave has made a great suggestion and going slow is always best. You might want to get a reactor and some GFO but I would only use about 1" of GFO in the reactor. You dont need much and you dont want to strip the water of P04. Corals need some P04 in the water for growth. .03 is what most consider perfect and I use this number as my goal. I wish I was as on top of my testing as you. My tanks would look much better if I did.

 

[StirCrayzy]

Anyone try a local community college (or university) Biology dept? I heard years ago that they sometimes accept outside SW as test variety for case studies. Haventcheck around recently though

 

[sirrealism]

HMMM Thats a good idea. My daughter goes to USF and they have a large marine bio department. I will ask her to see if any of her friends are in that program. Maybe one of her sorority sisters.

 

[OneFishTwoFish]

Thanks for the kind words, sirrealism ! I'll probably begin the GFO experiment this weekend. Looking at reactors now.


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[OneFishTwoFish]

My GFO experiment has begun. I've added a Nextreef MR1 Reactor to my sump. It has a dedicated pump. Currently it's running all the time, but I can schedule its operation via my Apex. I added Aquamaxx GFO to the reactor. The suggested amount (on the label) was 1 gram per gallon. This worked out to exactly one inch of GFO at the bottom of the reactor as sirrealism suggested above. The flow through the reactor is adjusted so the material tumbles gently. It's tumbling in a 4-5 inch tall mass. I'll test daily to see what effect this has . . . .

 

[sirrealism]

Looking good.

 

[OneFishTwoFish]

So . . . in less than 48 hours, Phosphate level has dropped from 10+ to undetectable. I'm using a Salifert test kit and just might not be able to see the very very light shade of blue to determine accurate results. I have a Hanna Low-Range Phosphate Checker on the way. No panic yet. Not trying to 'chase numbers'. No visible differences exhibited by our tank inhabitants. Also - no change in Nitrates, still 1-2 (which I believe to be OK).

If I have sucked all of the Phosphate out, which would be the better approach:

1. Continue to run the GFO Reactor continuously, but with a smaller quantity of GFO.
2. Run the GFO Reactor on a schedule -- maybe 4 hours ON, followed by 4 hours OFF, etc.

Comments / suggestions welcome !
---Frank

 

[OneFishTwoFish]

Confirmed with Hanna Low-Range Phosphate Checker, Phosphate level is 0.00
I've shut-down the GFO reactor and will continue to monitor phosphates. I will continue to experiment with quantity of GFO in the reactor vs reactor run time.

 

[OneFishTwoFish]

Quick update on my quest for an acceptable phosphate level:

• GFO Reactor running for approx 47 hours brought Phosphates down from 0.10+ to 0.00
• GFO offline for approx 24 hours allowed Phosphates to rise from 0.00 to 0.07
• GFO on 'scheduled' operation for 48 hours. Now have Phosphates at 0.03

My GFO Reactor is Neptune Apex controlled to run for 10 minutes at the start of every other hour throughout the day (1am, 3am, 5am, etc.) It is still loaded with the 100 Grams of GFO that I started with. Operation has been unchanged for 48 hours. I'll continue to test daily.

 

[sirrealism]

Great job. I have never heard of someone running GFO for short times like this but if it works then great. My goal has always been to have my P04 at .03 so it looks like your right on target. I know some will say you want 0.00 but the truth is corals need very small amounts of P04 to grow. So to me it seems like you have this dialed in.