[xfatdannx]

So i have been fighting diatoms for the last 2 months. I have re planted with faster growing plants, i have changed lighting, and i have changed feeding sched. Lets assume i haven't done a thing yet and please suggest what to check first and i will try to figure it out.

ammonia - 0ppm
nitrite - 0ppm
nitrate - 20ppm (2 days from weekly w/c)
phosphates - 0
i did not check the ph but it should be around 6.8ish as i run co2 daily (on the light timer)
2 t5ho bulbs (5000k and 6500k) run together for about 6 - 6.5 hrs a day
20 gal tall
8 phantom tetras
2 german blue rams
plants: Italian Val, Madagascar lace, Ozelot Sword, Moneywort, Bacopa, Crypt Parva, and Crypt Spiralis
2 HOB filters one is the aquaclear 20 gal filter the other is the aqueon quite flow 10
i have 2 root tabs (one under madagascar lace one under ozelot sword)
feed them once per day, spektrum new life pellets, usually gone in under 30 seconds

let me know where you would check first, thank you!!!!

 

[Boredomb]

Silicates in your tap water??

 

[xfatdannx]

is there a way for me to test that? guy at the LFS also suggested going R/O...thoughts or comments?

 

[xfatdannx]

before going R/O i am trying one other thing. I have been told that i may have too low Co2 and should start my Co2 before i start my lights. Now my Co2 will come on an hour and a half before my lights, thus making an even shorter period in which the lights are on but Co2 is not at optimum levels.

 

[rickey]

I'm going with Boredomb on this one
A unique feature of diatom cells is that they are enclosed within a cell wall made of hydrated silicon dioxide which is chemically inert. This make testing challenging.
Is there a source of Silicates in the aquarium(Silica sand, etc)?
Is there Silicates in the source water?
Generally Diatom are self limiting as the silicon dioxide is used up so I would look for the silicate source

R

 

[jaysee]

With the exception of calcium sands and the like, almost all sands are silica sands. I wonder if the degree to which the sand is washed has an impact on diatoms.

 

[rickey]

With the exception of calcium sands and the like, almost all sands are silica sands. I wonder if the degree to which the sand is washed has an impact on diatoms.

The most common of sand in inland continental settings and non-tropical coastal settings is silica. Probably 90% of all sand is silica sand. The second most common type of sand is calcium carbonate. But I don't know if washing has an impact or not Why some silica sand are fine and another is a pain in the butt, it known in chemistry as the Universal Compound and there are somewhere around a dozen different oxide structure of silicon
R

 

[jaysee]

My guess is it has to do with the dust. Just a guess.

 

[Boredomb]

is there a way for me to test that? guy at the LFS also suggested gong R/O...thoughts or comments?

Sorry for the long delay with me responding!

To answer your question yes there are test that you can use to test for silicates in your water. However I don't know at what level of silicates it take for diatoms to thrive just know they will as long as the source is there. After doing a quick search here is one test kit. : Aquarium Water Testing: Salifert Silicate Test Kit

 

[rickey]

Lamotte Silica test but it ain't cheap
R

 

[xfatdannx]

edit: in response to the silicate tests: Maybe i should just take a tap sample to LFS and see if they will test silicates for me. I will call them tomorrow and see if they will do so.

If the co2 timing doesn't make a difference, basically RO would be the way to go, bc there would be none of those impurities leading to the diatoms?

if so, does anyone have a link to what REALLY needs to happen when running RO. LFS says "just add micro nutrients with excel comprehensive" everyone online just says "dont do it it will lead to more problems". Im trying to learn an neither case really has any evidence for me to sort though.

 

[Boredomb]

Going with straight RO can be expensive over time and a lot work to do water changes with.
You can see if the LFS can test your water for silicates before buying a test kit that you would probably only use once.

Another thing you can try is using a silicate remover in you tank such as this API Phos-Zorb: Phosphate & Silicate Removal Media for Fresh & Saltwater Aquariums There are other brands as well and I have heard they are effect and work. I can't honestly say as I have never ran into this problem. I can say tho it might be cheaper/easier in the long run then RO as then you have to buy minerals for the RO to add hardness back for the fish and plants.

 

[xfatdannx]

this week will be the real test. In the last few days i added a separate timer for the Co2 and also added duckweed to reduce direct light on the substrate. Let you know how it goes.

Boredomb, thanks for the help. After this next week of test i will go from there, that product sounds familiar though, i believe its at the LFS.

 

[Hallyx]

Just another data point (and to Jaysee about sand "dust"). I get diatoms in my bare-bottom tanks.