Mold/Algae/Cyanobacteria

[onefstsnake]

In my 75g Intermedius tank 2/3 of the back wall is a drip wall and stays pretty wet.
Problem is its covered in all sorts of nasty stuff. Im sure most of it is algae but some of it is fuzzy looking and green and other spots are black and smell very strongly.

Water flow is pretty good going down the wall and I have 3 48" T5 HO 6500k lights over the tank.

Ive turned off the pump to the drip wall for a week and everything dried up. I scraped most of it off the wall and turned the pump back on. A few days later the stuff is back...

Any ideas?

Also the front 1/3 of the tanks top is mesh, rest is glass.

[Toby_H]

A picture would help offer a possible identification. I've dealt with cyanobacteria in fish tanks quite a bit. It can be some persistent stuff...

The best solution to removing it from a fish tank is to starve the tank of natural sunlight or artificial lighting that replicates natural sunlight. So the use of “fancy” grow bulbs will feed the cyan bacteria, although you may need such lighting for the plants you keep. The dirt cheap bulbs I use on my fish tanks offer very little to photosynthesis.

Caynobacteria also requires some form of carbon source to thrive. This is usually provided through phosphates or nitrates. Phosphates are found in many municipal water sources and many fertilizers are phosphate based. Nitrates are the common result of the waste biodegrading.

Seachem makes a wide range of filtration medias with Purigen being at the top of the list. The manufacturer suggests it removes ammonia, nitrite & nitrate as well as phosphates. I’ve heard through long time users that it actually works as suggested.

Purigen is a bit pricey, but as it can be recharged quite easily, it is a one time purchase and then will work for years to come.


I can’t promise that Purigen will work for sure, but if I were in your shoes that is where I would start…


PS - Purigen is a filter media, meaning water will need to flow through it. I suggest incorporating it into the pump intake for your drip wall.

[onefstsnake]

Ok, Ill try to get some pics up in a bit.

I use distilled water for my misting system and I originally filled the tank with distilled as well. Surprisingly I havent had to add water to the tank since I first filled it about a year ago.

I once had java moss completely covering the entire back wall. But eventually it was consumed by the algae and other growth and died away.

[sk8erdave]

As a start i would start with some large scale water changes with r/o water to remove any waste feeding the cyano(blue green algae). And as a secondary method I have never tried purigen myself so i will not say if it is a good product or not, but i would personally just go for reliable phosban always worked for me in the past...
Dave

[onefstsnake]

Here are a few pics. Last one is just for fun, not showing algae.

[Toby_H]

Looks like Caynobacteria to me...

Hearing the background on your tank, it seems to make sense...

When the tank was fresh and new with distilled water, there were no phosphates or nitrates, thus no caynobacteria...

As the tank aged, frog waste broke down into nitrates and built up...

phosphates can also appear as the result of waste or plant matter biodegrading...

With the appearance and accumulation of nitrates and possibly phosphates... the prime environment for cyanobacteria formed...


Testing for nitrates and phosphates would be a great idea if it's practical. Most aquarium test kits test for nitrates and phosphate test kits aren't hard to find at aquarium supply stores.


A thorough water change is always an easy first step with freshwater systems... I agree with Dave it would be a good idea here...


To prevent the issue from reoccuring, you will want to either A) alter the lighting, or B) prevent the accumulation of nitrate and /or phosphates.

For A) I'm not sure what plants you have nor what their light needs are. I'm no pro with planted tanks but I do know that different spectrums support different things. THere may be bulbs that support plant life but do not support cyanobacteria as well...

For B) regular water changes are a great idea. This is the most common way aquarium keepers keep nitrates from building up to high. The use of a product that 'removes' phosphates and nitrates is also an option. No more biodegrading plants or waste your system will experience, I don't think you would need to change or recharge your media often at all.

[carbonetc]

Cyanobacteria is very dark green (almost black), covers things like a sheet, and smells very strongly.

I've read it thrives in water with lots of phosphates so I've considered putting a phosphate sponge (sold for aquariums) in my filter to fix my own cyano problem, but I haven't tried it yet so I can't vouch for it.

It also doesn't like fast-moving water, but you can only get that kind of current in an aquarium. Vivaria are a perfect home for this stuff.

It's a tough one to get rid of.

EDIT: A rather redundant post now. That's what I get for leaving to get a snack mid-paragraph.

[onefstsnake]

Ill try a few water changes. Unfortunately when I built the tank I didnt make the pump real easy to get to.

Thanks for the advice.