Pros and cons of Diatoms

[itafx]

I have a guppy fry tank with diatoms. The diatoms are starting to cover some of the plants. Can the guppies benefit from the diatoms by eating them or hiding in them? Do the diatoms damage the plants in any way other than shading them if they grow too much?

 

[Purrbox]

The only fish I've ever heard of eatng diatoms is otos. The diatoms really shouldn't hurt the plants as long as it doesn't shade them too much by becoming too thick. Luckily this is easily prevented by lightly brushing the diatoms off of the plants.

 

[itafx]

Fortunately, these are mostly free floating Anacharis. I can take the plants out, rinse the diatoms off, and put them back in the tank. I just didn't want to do it if the diatoms were benefiting the fry.

 

[Peyton]

Like purrbox mentioned ottos do a good job of controling diatoms and they will not harm the guppy fry. Personally, I doubt if the guppies are eating the diatoms. Is this a new tank? I ask because it's often normal in newly setup tanks to see a brown diatom outbreak.

 

[itafx]

It is a fairly new tank. I've always wondered why newer tanks tend to do this so much more than old tanks. I think there are more diatoms than an otto could eat in a life time. I haven't done anything yet since I didn't consider it to be very harmful. At this point, the diatom volume probably fills 20% of the tank.

 

[Purrbox]

Diatoms feed on sylicates which are abundant in new aquariums. Once these are consumed the Diatoms die off. As long as there isn't a constant source of sylicates being supplied to the aquarium in the water or leeching from the decor, it goes away in a few weeks.

 

[Zezmo]

hiding in them?

At this point, the diatom volume probably fills 20% of the tank.

A couple of your comments lead me to think you do not have diatoms. Diatoms are a thin brown film coating things. They can not be hidden in, and they can not fill any tank volume. There are other algaes besides diatoms that are brown. There is a type of brown algae that looks like big cottony puffs of brown slimyness. This sounds more like what you have. They can be caused by high DOC's or just nutrient imbalance.

 

[Purrbox]

Good catch Zezmo. I agree that those two statements make it less likely that you're dealing with Diatoms. Both the high DOCs and Nutrient Imbalance are best addressed by a large water change followed by dosing your ferts to the appropriate levels.