to siphon the gravel bed.
 

the problem is everytime i do ,a few hours later i have a diatom bloom,which does go away after a few days ,but in that time looks ugly on the sand,is it possible to not siphon the gravel and just do a water change without disturbing the sand bed letting the crabs etc do this thanks.

Re: to siphon the gravel bed.
 

if you siphon the sand bed you basicly lose what it is there for. I do not siphon my sandbed. Well, I am slowly removing my sandbed.. but that is a different story. When you siphon your sandbed you are also taking out little critters that are helping your tank break down waste etc.

I like to stir up the sand a bit with a baster or big syringe then do my water change. That gets a lot of the settled junk into the water column where it is either removed with the water change or in the hang-on filter, which I also rinse / change shortly after the water.

As per what Chad said...

thanks
 

thanks for the posts ,from this point on i shall leave my sand bed alone :)

I would vacuum it as much as you can because your sand bed eventually becomes a nitrate trap. A cleanup crew won't get rid of your nitrates, they will just breakdown the uneaten food or waste before it becomes ammonia, and won't erradicate the nitrate.

There are people that swear by deep sand beds (DSB), but I have heard many people move to shallow to no sand beds. There are also alot of people that testify that a tank may experience a sudden wipout syndrome which is believed to be attributed to a deep sand bed.

:rolleyes: As far as I know, there is very little good empirical evidence disproving the effectiveness of the DSB concept. On the other hand, there is very little proving it. If you are trying to achieve a DSB, I wouldn't vacuum it. Otherwise, do as you see fit.

Unless you are using coarse crushed coral you shouldn't need to siphon your sandbed. You're probably doing more harm than good, which is proven with your diatom blooms.

Brisk circulation should prevent most detritus settling in your reef. Maybe try out a small AquaClear mechanical filter to polish your water but just make sure you change or rinse the floss/foam very frequently to prevent a "nitrate factory."

If you're still worried about detritus a small cleanup crew wouldn't hurt. Hermits and Cerith snails are great sandbed cleaners.

But, obviously you've found out that messing with the sandbed disrupts the tank and causes a diatom bloom... so stop. You'll be fine with just plain water changes.

Hope that helps.

I think you mean to say "phosphates" not "nitrates." A sand bed, just like live rock, has no trouble managing nitrates (in moderation), as per the nitrogen cycle.... It's the phosphates that have nowhere to go and that end up binding to the calcium precipitates.

if you have a shallow bed (1 inch or so) stirring it regularly will be beneficial, but if you are going for the deep sand bed leave it alone.

Steve