free floating algae

[kcooley]

i have had a recurring problem with a free floating algae in my tank, i was wondering if anyone has had the same problem or may know a way to get rid of it.

i have a planted tank using laterite as a substrate with pea gravel on top. it is a discus community tank. i used a UV filter the fist time to get rid of it and it came back after i moved some of the plants in my tank. when i move plants the laterite i use clouds the water like clay, and a few days after it will turn green. water changes hardly affect this, even up to 70%. i was wondering if there is another way to get rid of this problem.

my tank perameters are normal,
Ph. 7.2
gh 4
kh 4
ammonia, nitrate, nitrite...0

[kcooley]

i forgot to mention that visibility is limited to about 4-6"

[phanmc]

How thick is the layer of gravel above the laterite? you should have at least 2 inches of gravel over the laterite and shouldn't be stirring it up easily. Are you dosing ferts? what is the wattage per gallon?

You basically have a nutrient imbalance. Longterm solution would be to get more fast growing plants to outcompete the algae, short term is to continue to use the UV sterilizer.

[kcooley]

i took out over 50% of my plants and that is what stirred up the mess.

i am adding liquid gold(iron /phosphate) twice weekly. i have between 1 1/2 - 2 inches gravel over the laterite.

[phanmc]

What kind of lighting do you have? How big of a tank?

What kind of plants do you still have?

Your fert dosing should include potassium, nitrates (keep nitrates around 10-15ppm), and micro nutrients other than iron. If you don't know what to use, I recommend Seachem's line of Flourish products or ordering the raw ingredients from www.gregwatson.com.

[kcooley]

i also use flourish once a week.

it is a 55g, with 2 amazon swords, ludwigia, rotala, dwarf swords, bamboo, vals, spiralis, about 20 crypts too.

i have 2 40W 48" flourescents.

would trapped poo in the gravel around plants roots have an affect, possibly leeching nitrates out at alarming levels?

i dont think it has anything to do with the green water or algae itself, but the last 20 times my discus have laid eggs they have died off between 36-48 hours every time.

[phanmc]

If the mulm was leeching nitrates into the water, your nitrate test would pick it up. Your result of 0 seems to indicate that excess nitrates isn't the cause, though nitrate deficiency may be involved. I'm thinking an excess amount of phosphate is more likely since you're dosing that and not nitrates or potassium. Dose potassium for sure and try to keep your nitrates around 10-15ppm.

How does your plants look? are they healthy and growing?

[kcooley]

my ludwigia seems to grow about 1/2" daily when it is cloudy, but only little bits when it isnt. my rotala has taken off so many times that i have to cut it every 2 weeks. my swords are bright green with no holes in the leaves. my val has started to brown, but alot of it isnt very well planted.

could i take all of the plants out and vacuum the gravel and replant? i vacuumed 1/3 2 days ago.

[jm1212]

you could try a UV sterilizer, but i have only heard of them being used for saltwater aquariums, but it would work in this situation, since one of their uses is to get rid of "green water"

[phanmc]

You don't want to disturb the laterite too much so I wouldn't recommend yanking all the plants out. I still think the issue is excess phosphates and lack of nitrates or potassium. Use the UV sterilizer for a temp fix and either cut back on the liquid gold or start adding the other macros. Adding CO2 or Flourish Excel may help out too.

[kcooley]

i did another wc last night and put the full amount of prime in the water 5X.

i have a phosphate remover resin in my canister. can i put more in than recommended?