WHY oh WHY ?

[UH_OH_5_OH]

.....do I have phosphates...? My phosphates are at 0.25 and I have noticed a few teeny tiny strands of hair algae in the back corner of my tank.

Please help 'splain this to me....I have a 135gal with a ASM2 skimmer that runs 24/7....I have two 250Watt MH fixtures with 20K bulbs in them...I only use RO water ( my RO components were changed out, membrane and both inserts, three months ago. I feed my Sailfin, two damsels and cherub angel sparingly because they are all always grazing in the tank on nuisance algae that grew thanks to my previous bunk MH 10K bulbs.

I have a refug with a good size piece of liverock (softball) and two large clumps of chaeto algae in it.

These are my water results as of two days ago:
pH 8.3, SG 1.024, CA 386, A- 0, N- 0, KH- 6, and phos-0.25

What is causing the phosphates to go up....and my KH ???

I am too new at this to be scrambling around trying to figure this out....someone spell it out for me...and use pictures !

[fsn77]

What kind of food do you feed the tank? Food brings phosphate into your tank. Dried flakes and pellets can be pretty high in phosphate, although there are brands that do contain less than others.

You say RO water -- does it also have a DI cartridge (deionization) after the RO membrane? Without a DI cartridge, you won't remove all of the phosphates.

[UH_OH_5_OH]

The food I use is all frozen mysis shrimp, brine shrimp and muscles

as for a DI cartridge....hmmmm...I dunno. I have two cartridges. One that is a white fibreous material and the other that looks like a charcoal cylinder. What does a DI cartridge look like...?

[UH_OH_5_OH]

........AND will running a hot magnum with charcoal help this phos problem...?

[fsn77]

A DI cartridge would be after your RO membrane and look similar to this (http://www.purelyh2o.com/product.php?productid=16162&cat=256&page=1).

Do you rinse your frozen foods before feeding them to the tank? The liquid from them can be high in phosphates, also. I use a fine mesh fish net to rinse frozen mysis. The cube goes in the net and into a cup of RO/DI. After it thaws, I rinse it with another cup of RO/DI, then it gets fed to the tank.

Running carbon in your system will not remove phosphates. In fact, most brands of carbon can actually leach additional phosphates into the water. There are specific ones designed for reef tanks that are suppose to release lesser amounts of phosphates, like Kent Reef Carbon (http://www.marinedepot.com/md_viewItem.asp?idproduct=KM9171) and the one made by Two Little Fishies (http://www.marinedepot.com/md_viewItem.asp?idproduct=TL1171).

[UH_OH_5_OH]

Geez oh pete ! ! ! Okay no, I don't rinse my frozen foods first... at least I didn't use to....I will from now on....! Thanks for the intel I will put it to good use ! ! !

[UH_OH_5_OH]

fsn77.........follow up question for you ! I have a Kent Marine system with two cylinders underneath the membrane....does a DI cartridge come standard with that....?

[bertoni]

That sounds like a RO system without a DI unit. You can add a DI unit if you choose.

I wouldn't expect carbon to reduce phosphate much, due to limited filtering capacity, and some other issues (I don't think it'll bind phosphate ions directly).

As far as rinsing food, that's okay for whole items like many brine shrimp and mysid shrimp products. I don't do that with a prepared food like Formula 1 that contains ground food items. I worry about flushing too many nutrients, especially water-soluble ones, down the drain.

A phosphate reactor or growing and harvesting a macroalga can help with phosphate problems. This article discusses a number of approaches:

http://www.advancedaquarist.com/issues/sept2002/chem.htm