phosphate & nitrate useage by chaeto

[Chad Vossen]

i currently have a massive refuge attached to my 65 gallon tank. the tank itself is only two months old, i know its got more matureing to do. but i cant help but notice that i seem to always have phosphates, but a cheap nitrate test showed 0.
after reading up alittle, it seems that calerpa takes up much more nitrogen than it does phosphates and i assume that chaeto is very similar.
so, would it make sense to begin doseing Nitrate into my tank as it seems to be the limiting factor in my chaeto growth. would i reduce my phosphates this way?

it seems well known that the hair algae is able to survive and grow in low concentrations of nitrate and may depend more on phosphates.

so would doseing nitrate to encourage more fuge activity actually speed up the useage of phosphates?

sorry if my questions and ideas seem messy, if you understand what im getting at, please comment. i do have a skimmer on the tank however its not "great" and i focus my filtration on my fuge.

 

[PatrikS]

I can speak only for myself, but I dose KNO3 as a source for nitrates in order to reduce phosphates.

 

[piercho]

it seems well known that the hair algae is able to survive and grow in low concentrations of nitrate and may depend more on phosphates

This is, as far as I know, reef mythology. Some of the cyanobacteria can fix nitrogen for production, but not hair algae which is usually a green algae. Green algae cannot fix nitrogen, it must take up nitrogen as a nutrient and the N of green algae tissues are typically high, like 30:1 and higher. Some Caulerpa can have uptake N above 200:1. The algae in tanks with detectable phosphate are being limited, they would take up the phosphate if they could but there is not enough of something - nitrate, iron, light, gas exchange - to allow them to.

would doseing nitrate to encourage more fuge activity actually speed up the useage of phosphates?

If you are certain that you have measurable orthophsophate with no measurable nitrate I would add KNO3. More flow through the refugia and more light over the refugia should also help to increase uptake of phosphate.

 

[Chad Vossen]

what are some other ways to reduce phosphates WITHOUT useing any media? im trying to run my tank as natural as i can, but i do have a skimmer helping alittle.

 

[graveyardworm]

If you are feeding prepared frozen foods then it would be helpful to thaw and rinse the food first, there' is generally alot of excess PO4 in the liquid.

Welcome to Reef Central PatrikS

I also dose KNO3 to help my macros utilize more PO4.

 

[piercho]

You can continue skimming. Skimming is effective to remove organics rich in P. Otherwise, increasing the flow through your Chaeto filter and possibly increasing the light intensity over your Chaeto filter may help.

 

[Chad Vossen]

where can i find PNO3?

 

[piercho]

I think you want KNO3, potassium nitrate. The cheapest way is to find stump killer at a hardware or garden center that is made up of KNO3. I would get the MSDS from the manufacturer to verify that the product is indeed KN03. Otherwise, check some of these sources for potassium nitrate listed on the Kribb.

 

[Chad Vossen]

adding "stump killer" to my reef tank sounds interesting. the name raises a few red flags, but ill look for it next time im in home depot lol.

Thankyou!

 

[graveyardworm]

Its called stump remover, here's the stuff I'm using. I bought it at Lowes, it was located with the pesticides and fertilizers.

My google search for green light stump remover yielded some interesting links, here's one. http://www.csd.net/~cgadd/aqua/art_plant_nitrate.htm