Need some suggestions

[stang5_o]

Ok, here goes. I've only been in this hobby for about 8 months, and i've learned a lot in that time. Im addicted, and now have 3 tanks. The only problem is, my first tank, a 46 gal bowfront. I started the tank before i discovered these boards, and made a lot of mistakes that arent easily corrected. The one that is turning out to be a problem is my sandbed. It always looks like crap. I have a sandsifting star, and about 75 nassaurius snails to keep the top stirred up, but it doesnt help. I think it may be because i used walmart play sand. The bag didnt say what it was made of, but it was white and looked good at first. I did the vinegar test and it did fizz a little, but not much. I keep getting cyano in one corner no matter how i adjust the flow. I have never had a problem with any other kind of algae. The rest of the sand usually looks kinda brownish with green and red speckles. I hate this because the rockwork is so pretty and clean looking. The other problem is that my rock is sitting directly on the bottom of the tank and the sand was added around the rock, which i have learned is not a good thing. All corals and other inhabitants are very healthy and seem to be thriving.
The tank is almost 8 months old, and i have coraline starting to cover everything, which I like. So, my question is, is there anything I can do remedy my problems with out a complete teardown? I dont have anywhere to put all the tank inhabitants, and I dont want to do anything that is going to cause a crash. Should I change out the sandbed slowly? Or should I just add the right kind of sand on top of whats there? If I have to tear it all down, what can i do to make the change as stress free for everthing living in the tank? I could put it all in tubs, but if I do that, will I have to go through the long process of cylcling the tank again?
For equipment, I have two 240 gph powerheads facing the front of the tank from the back corners about half way down. One facing slightly up, and one facing slightly down. I have a large HOB power filter that is kept very clean. For a skimmer i have a Sealcone 100. I know its junk, but for now thats all I have until I can afford a better one. I also have a 110gph powerhead near the surface in the rear of the tank facing straight up to keep the surface agitated. I have been doing weekly 15 gal waterchanges using distilled water (which adds up to a lot of $ after a while) for the last 3 weeks, and I did 10 gal bi weekly before that.
Sooo, if anyone has any ideas lets hear em. I want my tank to look like the ones i see in pictures with a nice white clean sandbed.

 

[mrdc]

Make sure the areas are getting adequate flow. I noticed that the left and right side show algea and those can be harder areas to reach. Two, you have plenty of nass snails IMO but I would go with some sand sifting conches. Conches have done more for my sand than anything else and again that is my opinion. Three, how much are you feeding? Four, have you tested your phosphate level? I ask because I feed a lot even though I do weekly water changes and I started to get some red algae and so I started using some phos sponge and it helped me alot. Well thats all I got to say for now

 

[stang5_o]

I havent tested the phosphates because i dont have a test kit for them, but i have been running the phos sponge just as a precaution. Your right, I am having trouble getting good flow in both rear corners.

 

[iluvreefs]

Another thing to think about as well is the distilled water you are using. When distilled water is being made, it runs through copper pipes which are not good for a SW reef tank or a FOWLR. Consider going to a store that has the Culligan water machine. For me it's 39 cents a gallon and it's RO/DI water. That's my solution for my current situation until I can purchase a RO/DI system and then figure out where in the world to put it in my house. You may also need to purchase a couple more PH and locate them more towards the bottom to get to those dead areas. I'm just passing information on that was once given to me.