[pgsasi]

Hello,
I change water in my tank every weekend. Mine is a 160L tank and I change 40L every week. but 2 days after the water change, there is a brown layer that forms on top of the sand. This happens every week.

also I see red colored worms growing in my tank in the sand. I take out a lot when I clean the sand with my tube. these are small, thin thread like structures..

can someone help me with finding out what is going on in my tank please.

Cheers
sasHi

[Ninong]

The "brown stuff" sounds like diatoms. Since you are seeing them shortly after a water change, it means that your source water contains silicate. Diatoms require silicate for skeletal formation.

Changing 25% of the water every week is really extreme in my opinion. I wouldn't change more than 5% per week or perhaps 10% every other week. My personal preference is for 15% every four to six weeks.

It is important that your source water be as pure as possible before mixing it with the salt mix, assuming you are using an artificial salt mix and not natural seawater. R.O./D.I. is the most common treatment for water for reef aquaria but some aquarists get by using distilled water purchased from their local supermarket, assuming their tank is not very large.

P.S. -- I wouldn't be too concerned about the worms in the sand. They are probably beneficial scavengers.

[pgsasi]

Hi Ninong,
Thanks for the reply. Right now I am using tap water and using chlorine neutralizer to get rid of the chlorine. RO water is available but I haven't tried it yet. I will get my tap water tested for silicates. The local pet shop guy asked me to change the water every week...40L every week and 80L once in 3 weeks...let me stop doing that any further more.

& Let me leave the worms....Cheers

sasHi

[Ninong]

If you are using tapwater and you notice a diatom bloom shortly after every water change, then it means your tapwater has silicate. It could also have other "nasties" that you are not aware of. Simply treating the tapwater with dechlorination drops (usually sodium thiosulfate) is not enough to make it suitable for a reef aquarium in most cases.

The reason the store recommends frequent water changes is because that's what they probably do to manage water quality in their holding tanks. That's a different ball game altogether. In your case, you are looking for long-term stability in a reef aquarium. Twenty-five percent weekly water changes, in my opinion, do not promote long-term stability.

If you prefer to do weekly water changes, I would limit them to no more than 10% but I think 5% would be better. Better still, in my opinion, would be 10%-15% every three or four weeks. I just think that 25% per week is too much for a reef aquarium. That's common procedure for planted freshwater tanks but not reef tanks.

[pgsasi]

Hi Ninong,
From what you say, I have been trying to fight something that will never stop !! I think its time for me to go for a RO apparatus. Will RO apparatus remove all the unwanted things in my water and make it suitable for my tank ? please let me know..Thank you for your support always

Cheers
sasHi

[Ninong]

You should consider purchasing an R.O./D.I. unit.

[Frodo]

Originally Posted by Ninong

You should consider purchasing an R.O./D.I. unit.

Best purchase for a reef tank owner

[shaywood]

I use RO water and do about 10% water change a week. Still get the brownies before long. I've never been able to avoid them! Is there a test kit for silicates.

[pgsasi]

HI,
The brown layer is spreading to the sides of my tank now. small bubbles have started showing up in the brown layer..is there anyway to stop silicates from entering the tank ? any kits to remove silicates...

[Ninong]

Diatom blooms usually last no more than about two weeks and then they just disappear on their own.

[pgsasi]

thanks for the help Ninong..I will wait for another week and update here....

Cheers
sasHi