haytrev

i am having problems with filamentous algae caused by high nitrate levels.i have done a partial water change in the last 36 hours and the nitrate level has stayed the same and the filamentous algae has started spreading across the gravel again.can anyone help?:

Peterpiper

What are the readings for the nitrates? and what % of water was changed?

haytrev

nitrites were 0 nitrates 25.changed approx 30% of water.

Peterpiper

Somethings not right, if you had a reading of 25 and did a 30% WC the nitrates should have droped to 17.... which test kit are you using?

haytrev

im using a tetra test kit.(5 in 1 test strips)

Peterpiper

And here is the problem! they are rubbish, they are giving you a false reading. The test kit that most use are the API Test kits. If you can take some of the water to the LFS and have them test it for you. I would look at getting the API Kit and do a 50% water change.

haytrev

if these are giving me a false reading then why am i getting the filamentous algae spreading so quickly after doing a water change?

Peterpiper

Your nitrates could be a lot higher than what the test is showing. As you say the algae is due to the high nitrates and if the nitrates are high you may not have reduced them enough with a 30% WC.
What type of lighting do you have and how long is it on for?

haytrev

2 * T5 flourescent tubes
the lights are on for 9 hours a day.

Peterpiper

With the flouro's, after about 9 months they should be replaced as the light starts to go into the red spectrum, and algaes grow more.
It may be a combination of the nitrates and the lights if the lights are more than 9 months old.
9 hrs a day is fine.
Sorry just seen your tank is 3 months old..

haytrev

okay.thanks for the help anyway.will do a 50% water change and will invest in a proper testing kit aswell.

haytrev

got the api test kit.nitrate level is reading 0 - 5 so nitrate level is very low but the filamentous algae is still spreading quickly across the gravel.

Peterpiper

Ok, the algae must have a supply of food coming from somewhere. Have you checked your water for Phosphates?

susitna-flower

Hi, Haytrev, most here swear by the API Master test kit, and I see you have gotten one but are getting a reading of 0 for nitrate with it.....


May I suggest you give Nitrate Bottle #2 a VERY vigorous shaking for over a minute, you have to strike it on something hard as you shake.......Sitting in the store for no telling how long the chemicals in that bottle crystallize.....You have to do the above if it has not been used for awhile....If you use it every day, just a good shake for a minute will do it....

You will get a true reading this way.

haytrev

thanks susitna-flower. have done this and the new reading is approx 20 for the nitrates.

haytrev

sorry to be a pain Pete but how do i test water for phosphates?

Butterfly

You have to buy a separate phosphate test.

Algae is caused by having excess nutrients (fish food, fish poo, decaying plants etc) and light.
Since a fishes stomach is the size of one eye cutting down how much your feeding, doing a 50% water change and a gravel vacuum(this will remove some of the excess nutrients in the tank) may help.
If after a couple of weeks you don't see an improvement a total black out may be needed.

What plants do you have in your tank? Fast growing plants, like stem and floating plants will out compete the algae for the food and light.

Do you have any algae eating fish?

My
Carol

Peterpiper

No need to be sorry and your not a pain! How can we learn without asking about things we dont know. It's one of the things that make Fishlore so good.