Change sand bed

[hkgar]

My tank has been set up for about 7 years and has a deep sand bed.

How important (or what are the pro's and con's) is changing the sand bed?

PO4 and nitrates were great for over 6 years and then suddenly started to be a problem. So I started dosing vodka and have switched to vinegar and they are both now at zero. I dose 50 ml in my 90 with a 20 gallon sump.

I have recently read that the breakdown of the sand bed is probably the cause of the high Phos. and Nitrates.

Here is a pic of my tank.

Tearing it all down to rubbermaid tubs for the change over would be a major task. Specifically with all of the encrusted SPS.

What is everyone's advice?

Also, which pic you like best, the whiter one or the bluer on? I have AI LED's

 

[swcc]

yup..the teardown is a big task. It is up to you to decide whether to do it or not. pros are cleaner system, lower overall nutrient levels, clearer water, perhaps healthier for the corals and fish... cons are if not done, your tank could become too overloaded with nutrients and cause a system crash.

 

[mc-cro]

As much as I would hate to be the one to actually do it. I say that sand bed needs to come out. You will be amazed at the amount of crap (literally) that comes out of the sand.

I built my rockwork on the bottom of the tank, and then put the sand in. In 5yrs or so when I decide its time to change the sand, I can just siphon it out, the rocks wont collapse.

 

[hkgar]

I built my rockwork on the bottom of the tank, and then put the sand in. In 5yrs or so when I decide its time to change the sand, I can just siphon it out, the rocks wont collapse.[/QUOTE]

How would you get the sand out without also taking all the water out?

i have about 100 lbs of sand and could siphon, but it would seem to also take out a whole lot of water.

 

[mc-cro]

It will take a lot of water out with the sand, but thats okay, its just a really large water change. You would want to make sure the water matches up, salinty, alk, and calc, but past that it should be just fine. If having that much water available is a challenge, it can be done in sections too. Do the left side this week, make more water, do the right side next week or the week after or so.

 

[mc-cro]

dont forget, there may be a risk of nitrates spiking if you remove too much of the sand at once. You need to give the tank time to balance itself, not much time, but a week or two is what I would do.

 

[bertoni]

Personally, I'd just work on nutrient control, but you could replace or eliminate the sand instead. It's a personal choice as to what you want to do. Keeping the sand might mean reducing the feeding rate, which could be fine or not, depending on your personal preferences for your tank.

What animals are in the system?

 

[hkgar]

What animals are in the system?

The fish are;
Coral Beauty
Yellow Tang
Royal Gramma
Clarki Clown
Blueheaded Wrasse

and snails and hermit crabs

 

[bertoni]

Those fish shouldn't cause any problems with the sand bed. How you proceed is up to you. I'd probably just work on nutrient control and wait, but for me, a few months to solve the problem wouldn't be a problem.