phosphate help please

[Angus]

Hi all

I'm new to the forum and i have had my 70G discus tank for ~13 months or so. A question for you experts:

My phosphate levels are through the roof (>5.0mg/L) which i discovered three weeks ago since buying a testkit. I have been doing larger water changes (50-70%) since then, thorough vacuuming etc and reducing the amount of food (i now realise i have been overfeeding in the past).

Despite this, i have not been able to lower the reading (the testkit scale's highest reading is 5mg/L).

A month or so before the discovery, I added discus buffer (what was i thinking!). Could this be the cause of the continued high levels? Will continued large water changes and cleaning eventually reduce the phosphate levels?

There are no phosphates in the water supply.

All the fish are healthy and happy but i'm wary of a large algae outbreak (i have a small brown algae problem which i attribute to this and old bulbs in a small W/G ratio)

I usually do ~35% water changes weekly with gravel and tank clean, and filter cleans every second week.

Medium to low planted tank

8 discus

4 clown loaches (i know i know but everbody is happy :lol: )

6 rummy nose tetra

3 cardinals

ph 7.2

kh 5.5

nitrites 0

nitrates ~5mg/L

DIY CO2 injection with no reactor yet

Your help/suggestions would be much appreciated

Cheers

Angus

[suphew]

Your CO2 wont be doing much with out a reactor, which might be a good thing if your light isn't much good. I would replace/increase the tubes asap to help get the nitrates down.

You could buy a bag of phos-sorb (about $25) and put it into your filter. But first I would stop feeding for a week (or at least a few days) but dont change anything that you do, i.e. keep doing the water changes etc. Then test to see if the phosphates have dropped, if they do then you are still over feeding (or you have poor quality food), if they dont then you need to look for othr causes.

Do you add fertizer to the tank? Some of these have phosphate in them.

Did you add anything to the substrate, like peat etc? Maybe it is leaching from that?

[Angus]

cheers suphew

i realised the co2 aint much good a little while back - i have parts for a diy reactor coming soon (i hope)

And just yesterday i replaced the old tubes and bought another tube so have 90W in total (low still i know but with a 4 foot total length 120W is the max i can cram in - is this true?)

i am feeding a range of rinsed bloodworm, rinsed discus tucker, flake (<1.5% PO4), colourbits (<1.5%), and greens (can't remember the name i'm at work). The amount is now so small, that all is consumed now in under two minutes and with clown loaches hovering underneath, i'm hoping leftover and waste is negligable. Still, i will do as you suggest, stop feeding to try and eliminate that side of things.

i have added a fertilizer but there aren't any phosphates listed.

Nothing added to the substrate. It is plain old river gravel about 13 months old from the lfs. I wouldn't have thought it would break down and leach phosphates????

I'm happy to buy a bag of phos-sorb if it'll fit into the eheim 2215 and other methods don't help....

Once again thanks for your advice :lol:

[suphew]

If your running a cannister filter feed the CO2 tube into the intake, by the time it comes out it will be well diffused.

Once you have tried the feeding test, I would stop using the fertilizer, unless it has it written on it that it has no phosphates, there is a good chance that it does. Also because you light isn't very strong you proberly dont need it, there are ways to tell if you are missing any nutuirents, I posted a chart in the plants sections a few months ago but it is on the net if you look around. Tells you things like, brown spots is lack of..., holes in leaves is lack of... etc

FYI I run just under 150w on my 4foot and would put more if I was still serious about growing plants, I have removed the CO2 as well. I got sick of putting so much effort into growing plants and then pulling out a bucket full each week. NOw it gets a tidy each week and a good clean out every month or so.

Phos-sorb type stuff is good, I'm surprised more freshwater people dont use it, a lot (most?) of marine tanks keepers do and swear by it.

[Angus]

boy - if i get to the stage of pulling handfuls of plants out each week, i'll be ecstatic!! (he says that now)

i guess i could check the phosphate level of the fertilizer myself by mixing and testing, but i don't go crazy on the stuff, only a small dose once every fortnight or so

sidetracking a bit - feeding the co2 into the intake wont affect the biological filtration at all? the reactor i've got planned is cool though - very diy

i'll keep testing, changing water, using your advice etc and let you know.

cheers

angus

[caserole]

I think you will find that the high phosphates are coming from the blood worms

have a friend with a CO2 injection system which developed a very bad alge problem, he track it back to high phosphate and the blood worms.

If you find that it is the b/worms creating your problem and still want to use them what he does to get around the phosphates is to sock them before feeding and discarding the socking water with most of the phosphates.

hope this helps

[dan_from_nz]

you may find your phosphates are not dropping because many phosphates are bound so will be leeching into the water as the waters phosphates are dropping making no change to your phosphate reading. I had a phosphate problem about a year ago and it took about 6 months of running jbl phos-ex (one pack a month) to get it down. It is also important you use a good food, with your discus because they have a short intestine track they require a high protine food you may find if your food has low protine you are having to feed them more creating more waste and leaching more phosphates into the water.

Good luck

Daniel