Algae Problem... are ORGANIC phosphates the issue?

[kenettson1]

I have a hair algae issue...

Here's the deal.

75 gal tank with 15 gal sump/ 125 lbs live rock.
I recently - 5 mos ago - switched out all my live rock that was almost completely infested with green hair algae with "new," uninfested live rock. I also got an air, water and ice 5 stage ro/di unit for top off and h20 changes, a new skimmer (Deltec AP600), and also run phosguard (change about every 5 days.

LaMotte Test kit says less than .05ppm phosphates in the tank and cheap digital TDS meter hooked up to RO says that output is usully 2-10 ppm on the top off.


I transfered the sand bed came from a previous tank that I did not take care of and was over run with hair algae.

My chemistry question is this:
Could ORGANIC phospahtes be leaching from the sand bed that are also not showing up on the test kits or being equally taken in by the NEW hair algae growing on the "new" rock?

Or could this be the "algae phase" that some newer tanks go through and I should just keep it up what I'm doing and it will go away?

I guess its frustrating because I feel like I'm doing everything right this time and I STILL have this issue with algae.

 

[Randy Holmes-Farley]

and cheap digital TDS meter hooked up to RO says that output is usully 2-10 ppm on the top off.

RO, or RO/DI?

Could ORGANIC phospahtes be leaching from the sand bed that are also not showing up on the test kits or being equally taken in by the NEW hair algae growing on the "new" rock?


Possible, but unlikely, IMO. I'd go after inorganic phosphate as that usually works. For example, treating with GFO, or growing a lot of macroalgae.

The phosphate can read low when there is a lot of algae simply because it is taking it all up, just as a lot of macroalgae will do. But taking the phosphate away from it can still reduce the problem.

 

[kenettson1]

RO/DI

 

[Randy Holmes-Farley]

While I doubt it is causing the algae problems, I recommend replacing DI cartridges as soon as the TDS rises above 0-1 ppm. Not because the TDS is a concern, but because certain nasties can be among the first ions released as the TDS rises.

This article has more:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm

from it:

http://www.reefkeeping.com/issues/2005-05/rhf/index.php#10

Monitor the DI resins by measuring the effluentââ"šÂ¬Ã¢"žÂ¢s conductivity, either with an inline meter (set to its most sensitive level), or by measuring the effluent manually. If you are using a TDS or conductivity meter, then the measured value should drop to near zero, or maybe 0-1 ppm TDS or 0-1 mS/cm. Higher values indicate that something is not functioning properly, or that the DI resin is becoming saturated and needs replacement. That does not necessarily mean, however, that 2 ppm TDS water is not OK to use. But beware that the flow of impurities and the conductivity may begin to rise fairly sharply when the resin becomes saturated. Do not agonize over 1 ppm versus zero ppm. While pure water has a TDS well below 1 ppm, uncertainties from carbon dioxide in the air (which gets into the water and ionizes to provide some conductivity; about 0.7 mS/cm for saturation with normal levels of CO2, possibly higher indoors) and the conductivity/TDS meter itself may yield results of 1 or 2 ppm even from totally pure water by not being exactly zeroed properly. Also note that the first impurities to leave the DI resin as it becomes saturated may be things that you are particularly concerned with (such as ammonia if your water supply uses chloramine or silica if there is a lot in the source water).

 

[kenettson1]

Thanks...
I'll pick up a new DI cartridge tomorrow first thing.

 

[Randy Holmes-Farley]

You're welcome.

Good luck.