too much phosphates

dski13 · 02-06-2013, 12:48 PM

So what are sources of phosphate? I got an API phosphate test kit a few weeks ago. At first my phosphates were low 0.5 ppm so I was adding potassium phosphate as a dry fertilizer. Recently I have been having high phosphates 5-10 ppm and I have obviously not been adding any more dry phosphate. Where could these phosphates be coming from. I have 7 guppies in the tank and a lot of snails. I am dosing KNO3, Sechem Comprehensive, and a small amount of excel for spot treating black brush algae. I do water changes once a week which brings phosphates down some but then they come back up as the week progresses. I am feeding Hikari tropical fancy guppy food which says min 1% phosphorus. Am I over feeding? I should also add that this is a 20 gallon tall dirted low tech tank with 3 T5 NO lights. Should I worry about having phoshpates that high? If I recall I want them around 1ppm.

Rainer · 02-06-2013, 02:23 PM

Fish food is a good source of PO4 for low tech tanks.

Older posts here indicated that levels up to 10ppm are harmless to fauna. I suggest researching this yourself before allowing your levels to get this high.

Wasserpest · 02-06-2013, 02:27 PM

Perhaps there are lots of phosphates in the dirt and they are leaching out slowly? I don't think overfeeding would lead to levels that high. If you are sure your tap water isn't phosphate enriched, and you are not dosing anything, I would suspect the substrate.

Rainer · 02-06-2013, 02:45 PM

Any chance that dissolved root tabs are being disturbed by water changes or osmocote nodules are disinterring themselves in a hidden area?

dski13 · 02-06-2013, 03:15 PM

I do not have any root tabs so it is not that. It could be the dirt but the tank has been set up for 3 months and this has only started in the past week or two. I will keep an eye on it and do water changes accordingly. Has anyone else used the API phosphate test? Any known sources of error?

02-06-2013, 12:48 PM	#1
dski13 Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Oct 2012 Location: Rhode Island Posts: 70	too much phosphates So what are sources of phosphate? I got an API phosphate test kit a few weeks ago. At first my phosphates were low 0.5 ppm so I was adding potassium phosphate as a dry fertilizer. Recently I have been having high phosphates 5-10 ppm and I have obviously not been adding any more dry phosphate. Where could these phosphates be coming from. I have 7 guppies in the tank and a lot of snails. I am dosing KNO3, Sechem Comprehensive, and a small amount of excel for spot treating black brush algae. I do water changes once a week which brings phosphates down some but then they come back up as the week progresses. I am feeding Hikari tropical fancy guppy food which says min 1% phosphorus. Am I over feeding? I should also add that this is a 20 gallon tall dirted low tech tank with 3 T5 NO lights. Should I worry about having phoshpates that high? If I recall I want them around 1ppm.

02-06-2013, 02:23 PM	#2
Rainer Wannabe Guru (View User Tanks) PTrader: (17/100%) Join Date: Jan 2011 Location: TN Posts: 1,518	Re: too much phosphates Fish food is a good source of PO4 for low tech tanks. Older posts here indicated that levels up to 10ppm are harmless to fauna. I suggest researching this yourself before allowing your levels to get this high. __________________ 29g high tech, 10g low tech halfmoon, and please see my 5g crescent journal.

02-06-2013, 02:27 PM	#3
Wasserpest Are these real? (View User Tanks) PTrader: (140/100%) Join Date: Jun 2003 Location: Monterey, CA Posts: 14,646	Perhaps there are lots of phosphates in the dirt and they are leaching out slowly? I don't think overfeeding would lead to levels that high. If you are sure your tap water isn't phosphate enriched, and you are not dosing anything, I would suspect the substrate. __________________ All my tanks Autodosing Water Change Temperature Monitoring Cheap Filter The Wasser-Controller

02-06-2013, 02:45 PM	#4
Rainer Wannabe Guru (View User Tanks) PTrader: (17/100%) Join Date: Jan 2011 Location: TN Posts: 1,518	Re: too much phosphates Any chance that dissolved root tabs are being disturbed by water changes or osmocote nodules are disinterring themselves in a hidden area? __________________ 29g high tech, 10g low tech halfmoon, and please see my 5g crescent journal.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

02-06-2013, 03:15 PM	#5
dski13 Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: Oct 2012 Location: Rhode Island Posts: 70	I do not have any root tabs so it is not that. It could be the dirt but the tank has been set up for 3 months and this has only started in the past week or two. I will keep an eye on it and do water changes accordingly. Has anyone else used the API phosphate test? Any known sources of error?