Why Do I Have Algae?

[wolfwolf]

Oaky, so I've read lots of websites, bought a book, followed the advice I've seen on this forum and I still have algae!!!

I have a 20 gallon planted tank. I have an aquaclear 30 filter and an aquaclear 30 powerhead (new three weeks ago). I also added co2 injection (currently running 3 hrs before the light and shuts off 1 hour before my lights). It runs at ~90 bubbles a minute. Lights are on 8 hours. The lights are T5 with a reflector. There are 2 bulbs at 14 watts a piece. 1.4WPG I dose flouirsh 1.8ml two times a week, Flourish trace 2.5ml twice a week. Flourish nitrogen 1 ml two times a week. Potassium 3 ml two times a week. I have 5-6 crypt wendti, 3 crypt spiralis. 5 stems of purple cabomba, 1 wisteria, 1 watersprite, and two annubias. they all have green algae and BBA. I also have green algae on the glass.

Things that I can test: ammonia-0, nitrite-0, nitrate-5, phosphate-0, kH-5, pH 7.4 at night 6.2 during the day.

I use an airstone as my co2 diffuser.

Fish 6X serpae tetra, 2Xkrib, 3X otto, 1X rubbernose plec.

What am I missing??? Do I need to add phosphate?


I have a 29 gallon tank planted without Co2 injection that uses the same style of bulbs but at 36watts. 1.2wpg. 1 ml flourish 2 a week, 2ml flourish excel everyday, flourish trace 2ml twice a week. The tank has 0 algae. I've actually moved plants from the 20 to the 29 and the algae dies in the 29 gallon tank.... what gives???

 

[Truck]

your plants probably arent getting much CO2 because of the airstone, switch to a diffuser. an ammonia reading may help.

 

[SexyFishKeeper]

Removed post as answer was in the original post!

 

[Dave Spencer]

they all have green algae and BBA. I also have green algae on the glass.

You don`t have enough CO2. Circulation may well be OK with the added powerhead, but the levels could be low.

nitrate-5, phosphate-0

Plants need phosphates. I suspect nitrates could be too low, but it is hard tell without a picture of the plant mass.

I use an airstone as my co2 diffuser.

Airstones are ineffective. Try a ceramic diffuser instead.

What am I missing??? Do I need to add phosphate?

Dave.

 

[julia298]

I would aim to have your nitrate levels between 10-20 then you know your plants are not being deprived of it, before you next add ferts.

you should definitely have phosphate, if your levels are zero, then this affects your plants growth lots. When plants not growing, well algae generally does. Have you got a test kit for this?

To check Co2 levels are high enough:
Take a sample of water and let it sit for 24 hrs - this tells you your normal PH (without CO2).
Then check your CO2 2hours after its been running. Test PH again.

If its pH (with Co2 running) is 1.0 whole level below normal ph - you are running CO2 at about 30ppm.
I run higher than this as I have high output lights.

If your air stone is casuing a lot of surface agitation, this will drive out some of your co2.

hth

 

[Truck]

If its pH (with Co2 running) is 1.0 whole level below normal ph - you are running CO2 at about 30ppm.

isnt KH a variable of this?

a DC would be the best way

 

[SuperColey1]

To check Co2 levels are high enough:
Take a sample of water and let it sit for 24 hrs - this tells you your normal PH (without CO2).
Then check your CO2 2hours after its been running. Test PH again.

If its pH (with Co2 running) is 1.0 whole level below normal ph - you are running CO2 at about 30ppm.

This doesn't work. different KH (as said above) will render different changes in Ph from the same concentration of CO2. Higher KH will see a smaller drop than lower KH. This is why Drop checkers use a known reference point of 4dKH which turns green on 25-35ppm (1 point drop) Some people who want less CO2 dilute their 4dKH to make 2dKH which then goes green at 12-25ppm!!!

I run higher than this as I have high output lights.

Lost me here. If you have higher light over the tank and enough circulation flow/nutrient dosing then the plants will grow faster and consume more CO2. Therefore we up the injection rate to maintain green in our DC. If your tank water is 4dKH then a 1 point is supposedly 30ppm (not allowing for all other kinds of acids that will lower the Ph!!!!) Therefore you want to maintain an injection rate that keeps the Ph at this 1 point drop.

Pushing it further without going the DC/dKH4 route is like a doctor administering injections of dangerous chemicals with a syringe that has no measurements on it!!!

I would doubt very much ifyour 1 point drop is 30ppm TBH. Even if you have 4/5dKH tank water then the acids within the tank will be letting you think you have more in there than you think you have. If you do have 30ppm and you are 'running higher than this' by using a point drop as 30ppm and pushing the drop further down then you have no idea how much CO2 is in there and endangering your livestock!!! If your water is high KH then this point drop could mean you are at very high levels. So watch the fish and the plants to make sure everything is OK in there

Firstly stop using the test kits. They will give you inaccurate answers that lead you to change things trying to correct an error that was not there in the first place.

If you are going the Seachem route then check out the whole dosing schedule on their website. I would personally just use EI with dry powders mixed into solutions as it is cheaper, easier and you won't have to worry about if you have enough of something in the tank until the plants have grown substantially (with no algae)

As Dave says every tank needs phosphate in it. Your tap will contain some but you need to add more for the plants to keep up with the CO2 addition and light.

In summary dose phosphate and get a drop checker

 

[wolfwolf]

Forgot to mention that I do have a drop checker. It shows green (but I would say green-blue more than green-yellow).

I'll have to get some phosphate ferts.

 

[wolfwolf]

Update. I have Flourish phosphorus on order. I could not find it at any of my LFS. They all preach that phosphate is the cause of algae. Therefore why would they sell it.

I bumped my co2 to 100 bubbles a minute.

I found a few glass diffusers online but they come in different sizes and I could not find any info about which size was good for a 20 gallon tank. Anyone have a recommendation?

 

[SuperColey1]

They all preach that phosphate is the cause of algae. Therefore why would they sell it.

Thats because most LFS are fish people, not planted people. lol.

We know different but may not have as much knowledge on fish (although I would probably say we are closer to the truth than them there also!!!)

AC