Some sort of algae?

[Rpbustillo]

I have a few small spots with this on it

 

[Rpbustillo]

Anybody?

 

[obscurereef]

Purplish cyano? What's the texture of it?

 

[Rpbustillo]

Soft and grows like a mat over the rock

 

[Crystal A]

Yup it's Cyanobacteria. Is that a low flow area?

 

[piperky1]

I am battling it too. I have had a power head pointed at it for a month or more. Still there. Guess I'm over feeding?

 

[Rpbustillo]

I only feed every other day one small pinch

 

[MINItron]

There is some source of nutrients for it to grow. It could even be phosphates that are locked into the rock it is growing on. Cyanobacteria cannot grow without food. Also the is an area of low water flow there. Cyano won't form a mat like that if there is good flow. You can use it to help export nutrients if you vacuum out the mat whenever it forms. Then the nutrients that it has absorbed from the rock will be removed from your system.

 

[Rpbustillo]

That has to be it bc the only places it grows is on two rocks that came from someone else's tanks

 

[MINItron]

Phosphates can become bound to aragonite. It is difficult to remove it, but Cyanobacteria can somehow harvest it as a food source. You can sometimes see the same thing if your sand or gravel becomes saturated with the stuff.

 

[Bray84]

I got it aswell and tired everything but keeps coming back but think tank is over stocked so going to get bigger tank in next few weeks and see if that helps

 

[MINItron]

I got it aswell and tired everything but keeps coming back but think tank is over stocked so going to get bigger tank in next few weeks and see if that helps

An overstocked or overfed tank will often have this problem. Old lights, old sand, lights on too long each day, low water flow all can be contributing factors. Keeping your calcium and carbonates up will help. Dosing with a carbon source such as vinegar or vodka can help as well.

 

[Rpbustillo]

Been thinking about carbon dosing how would you recommend dosing vodka??

 

[MINItron]

I use vinegar in conjunction with my kalkwasser for most of my top-up water. I only use half a teaspoon of lime for 2 liters of RO water and 2 tablespoons of white vinegar. It keeps my calcium and carbonate high enough that I occasionally see the formation of fresh sand in the bottom.

 

[Rpbustillo]

So just premix it with my top up water?

 

[MINItron]

I use a dripper made for reptiles that holds 2 liters of water, and has a plastic dripper valve. I put the lime in first and then the vinegar. The vinegar reacts with the lime dissolving it and converting it to calcium acetate. Then I fill it with water. The calcium acetate dissolves more quickly and completely than the calcium hydroxide. I drip it slowly into the take to avoid drastic pH swings, but even the one time that I had a valve malfunction and it all ran in a couple minutes there was no noticeable harm. Of course, I don't have any really sensitive livestock.

When the calcium gets really high I skip a day or two of kalkwasser and just dose with vinegar.

 

[Rpbustillo]

How long does it take for the 2L to drip into your tank?

 

[MINItron]

A couple of hours. 2 liters happens to be my averages loss per day so it works out ok.

 

[Rpbustillo]

A couple of hours. 2 liters happens to be my averages loss per day so it works out ok.

Wow how big is your tank? Thanks for the info

 

[MINItron]

Wow how big is your tank? Thanks for the info

I have a 29 gal with a refugium sump the holds about 5 gal. My actual capacity after rock and everything is around 30 gal. It is the 300 GPH circulation from the main tank to refugium that causes the evap. I never lost this much before adding the sump. The waterfalls from the the inlet box and bubble trap help with air exchange, but in add to evap.

I also use a homemade PVC overflow that has a long drop inside of the tank that mixes the water and air as it falls before it goes up and over the side.