Phosphate Help

[blanden.adam]

Hey Guys,

So, my reef tank has been up and running for the last 7 months, and thus far things have been going great. My tank currently has a mix of primarily SPS and LPS corals, with 1 toadstool leather, and 2 zoanthid colonies and an RBTA.

Here's my issue. For Christmas my lovely wife decided to get me, among other things, a hanna phosphate meter, and I tested the phosphate for the first time in my tank.. 0.00 ppm. I tested the water again, and got the same result.

Here's my dilemma, my corals have been doing well and are growing, but I'm not experienced enough to tell if their colors or growth rate are what they should be. Is this amount of phosphate too low?

Nuisance algae doesn't really grow -- I do get some film algae on the glass that I scrape off every couple of days and some diatoms that I wipe off the powerheads every month or so, but nothing on the rocks. I have chaeto that grows in the fuge, but recently it's growth rate has been very low.

Should I take steps to try and raise the level or should I just let it be?

The filtration of my tank relative to phosphate is as follows:

Tank: 29 gallon DT with 10 gallon sump
Skimmer: SWC 120 eXtreme cone skimmer
GAC/GFO: 20 tbs and 10 tbs in Two Little Fishes 150 reactor changed every month
Refugium: Rock rubble and Chaeto
Top-Off - RO/DI with 45 ml Vinegar and 1 tbs Mrs. Wages Pickling Lime/gallon

Other Parameters:

Calcium: 450 ppm
Alk: 8-9 dKH
Ammonia: 0
Nitrite: 0
Nitrate: 0
Salinity: 1.026
pH: 8.2
Temp: 79

 

[blanden.adam]

Oh, and I'm sorry!!! MERRY CHRISTMAS!!!

 

[bertoni]

Our test kits don't measure low enough to determine whether the phosphate level in a tank is at natural ocean levels. Unless the animals show signs of trouble, I'd leave the phosphate level alone. If you want to try to increase growth, you could try increasing the feeding a bit. That might help, if the corals are food-limited. They could be light-limited, or growing at about their maximum rate, though.

 

[kissman]

which Hanna checker is it? The ULR the 736 is a lot more accurate. The difference is that the UL reads in ppb and the others are in ppm. +-.04ppm or 4% is a lot different that +-5ppb or 5%

 

[bertoni]

The ULR reads in ppb phosphorus. The other checker reads in ppm phosphate. So you need to multiple the ULR reading by about 3. The ULR is rated as being a bit more accurate, but the difference isn't that large.

 

[blanden.adam]

It's the "other checker" that reads in ppm phosphate. I don't have it in front of me so I'm not sure what the number is.

 

[bertoni]

It's good to about ±0.04 ppm.

 

[blanden.adam]

Our test kits don't measure low enough to determine whether the phosphate level in a tank is at natural ocean levels. Unless the animals show signs of trouble, I'd leave the phosphate level alone. If you want to try to increase growth, you could try increasing the feeding a bit. That might help, if the corals are food-limited. They could be light-limited, or growing at about their maximum rate, though.

Thank you for the advice. Slightly increase nutrients with food as an experiment, but otherwise keep things as they are so as to not to risk messing up what I've got going. That is what I'll do.

What signs of trouble should I look for specifically? Just color loss and tissue necrosis?

 

[bertoni]

Color changes (browning) or tissue loss (at the higher levels) are both possibilities.

 

[aaroz]

Use lots of high color temp (20000k ish) HQI lighting or equavalent and watch the corals develop color. Coral color is not just for our entertainment but often as a response to protect growing cells from intense solar radiation.

I know it is not what most like to hear because it is the expensive option but is is a one off expense (plus electric! ), ALL of those 'color up formulas' are snake oil.

Ps good parameters! Although I am not convinced about vinegar

 

[blanden.adam]

I agree. The increased feeding did increase growth, but the colors still aren't where I would like them. I'm switching to MH and VHO lights and a larger tank either this week or next (whenever BRS get's their dosing pumps back in stock). All of the best looking tanks I've seen use that lighting, so perhaps I should too . I'm also going to stop the vinegar dosing in the new tank (switching to 2-part, no need to spike the kalk), and only start dosing it again if there is a compelling reason to do so (algae growth and whatnot). Thanks for the input!

 

[OnTheReef]

I'm switching to MH and VHO lights and a larger tank either this week or next (whenever BRS get's their dosing pumps back in stock).

I recommend switching to MH gradually. Run timers and increase the MH time an hour or two at a time. Otherwise, you can really fry your corals.

All of the best looking tanks I've seen use that lighting, so perhaps I should too .

Yep. I haven't seen anything hold a candle to MH lighting. I hear people claiming that the current generation of LEDs are getting there, but I want to see a tank lit with them before I believe it.

 

[aaroz]

Folks get SO worried about rapidly improving their systems, if you have crappy water CHANGE 100% of your water.
If you have crappy lights CHANGE YOUR LIGHTS!

What a reef wants is what it gets from mother nature, strong flow, strong light, fantastic water quality. Don't go being all timid just DO IT

If scared just raise the halide for a week or so.

Can anybody point out any advances in LED technology in REAL terms ie spectral output and improved CRI in the last few years??

All I see is the same CREE and SMD LED's encased in a huge variety of cases!

There is relatively zero money in this industry to develop a specific diodes, we just slap together whatever big industry demands lets hope they demand more variety of color to improve CRI.
That is the beauty of halides, metal salts can be mixed up easily and the number of wavelengths that flood out is just beyond the scope of LED and in my opinion will be for many many years.

 

[bertoni]

I'd raise the MH up and acclimate the corals carefully to the new light. Lights of people have had problems with lighting changes.