Diatoms/Dino's/Desperation

[MrsHaggis]

Hey Everyone,

The Bad News : I'm still having my diatom problem.
The Good News : I finally got my DI unit and now have full RO/DI water with a TDS of 0......yes 0!!!! Finally.

So, I done a silicate test on the new water but I still get a high silicate reading......any idea why? How reliable are those tests?

Next, I want to mix up some new salt water and test that for silicates.

So should I do a pretty big (30%) water change?
Or should I change the water more slowly than that?

I'm dosing Mag and Alk as they are a bit low.

Full water readings:

Salinity 1.025
Temp 26C
KH 7
PH 8 to 8.5
Ammonium 0.4 (had a fish die so it spiked ammonium - another reason to start doing big water changes)
Nitrite 0.05 (it always is)
Nitrate 0
Phosphate 0
Cal 340 (bit low but will come up when I dose Mag)
Mag 1260

Any comments/help/questions would be most appreciated.

Thanks
Fiona

[beeper man]

30% should be no problem. I had a similar situation and I have been doing 25% every other week for 6 months. Diatoms are better but phosphate is still .5. I'm sure it's coming out of live rock (150 lbs).

[MrsHaggis]

6 months of diatoms??
Oh Lordy!!! It's only been a few weeks and I'm at breaking point.......

[outy]

heres the deal

large water changes are fine as long as your not introducing more silicates. with 0 tds you should be fine.

now diatoms are feeding on the high amounts of silicates left in the water colum, manual removal of diatoms helps bring the silicate levels down. Use a turkey baster and blow the algea off the sand and rocks, clean the glass. use a fine mesh net to scoop it out and or run a small micron filter sock and clean daily.

best advise is to run alumina based phos removers as they will suck up the silicates better then gfo, this will be more effective then water changes. media should not be left in longer then a week