I still have Brown Diatoms

[Iclimb06]

I have been fighting diatoms since May. Most of what I have read about diatoms say that they only hang around until the silicates are used up. I have cranked up my lighting to about 14 hours a day trying to burn them out. I know that twelve hours is suggested, but after a couple months of that not helping, I figured if 12 will burn them 14 will burn them faster. However, I have also noticed that the diatoms do not grow in the shade of my decor. Also, I do a 30% water change every other week. I have also tried two methods of eradicating them. I have tried to let them grow and just cover everything that doesn’t move hoping that they would use up the silicates faster. The second method used is to try to super clean everything and remove them from the tank, yet after a couple days they are back. Either I have a ton of silicates, or there is something else going on.
I believe that I have heard something about the possibility that silicates are in the water. I have been using city tap water (obviously with dechlorinator) to do my water changes. How would I test for silicates?

Any suggestions as to how to win this fight would be greatly appreciated.

[Cameron]

i would suggest probably 30% a week, or maybe even 50% and continue cleaning i would think.

[terrapin24h]

do you use carbon? In my trials with said critters removing the carbon from my filters went along way towards reducing them. The second part of the equation was getting oto cats and apple snails. They are still evident in the tank, but are only a fraction of what they used to be. The other tank i had them in is the adf/gourami tank. They went down alot in that tank as well, but not as much as there isn't anything in ther that eats'm. They not only thrive on silicates, but phosphates, nitrates, and other dissolved organics; all of which can be leeched back into the water by carbon once it "fills up" and is old. Just a thought. I kind of stumbled on to it, as i pulled the carbon just because it made no sense to me to keep it. The i noticed after a wc or two "hey the brown crap is really died down". Both tanks are less than a year old. hth

--chris

[Iclimb06]

I do have old carbon in the cartridges. I have a penguin 200, and the only cartridges I have seen for it come prefilled with carbon. I have asked at the lfs if they make the cartridges that you can fill yourself, so that I could choose whether or not to use carbon, and they did not know of any. Also I am getting ready to cycle another tank so I have been leaving the cartridges in a little longer than I normally would so that I would have as much bacteria as possible for starting the new tank.
As far as Otos go, I bought two this summer. I noticed when I first got them that the diatoms seemed to be reduced. Then after a month or so it was like they just gave up. They both stayed in the back corner of the tank and rarely moved. They are in a 29 gallon, which is pictured in my avatar, and I think that they have plenty of places to hide. Their only tank mates are four zebras and a bamboo shrimp. About mid August, one of them died, and the other suddenly became active like they were when I first got them. The last three weeks I noticed that the remaining oto has been a bit sluggish and the other day I found him on the bottom. I immediately checked the water and the ammonia was 0 ppm, despite having a dead fish in the tank, nitrate was about 10 ppm and the rest was either 0 or normal.

[Sounguru]

#1 Live plants floaters being a good bet to suck up the extra nutirients.

#2 More Ottos ( you really need 6 for them to be happy) and snails nerites will do a great job if you don't want a population explosion

#3 cut back on feeding to remove nutrients for the stuff to use

#4 CO2 injection.

Cleaning and water changes will not cure the problem you need to make it so there is nothing for it to live on or that it is hostile for it to survive. There is a good chance all the nutrients needed are in your tap water to feed teh stuff.

[Northernguy]

Most lfs sell small bags that you can refill with activated carbon and ammonia pellets.You just fill the bags with the desired amount and rinse really well and add them to your filter.Just make sure you have room for a sponge on top.The sponge lasts longer than cotton and holds bacteria better when rinsed.You could probably look at an Aqua clear insert and get a better idea.