swapping out crushed coral

[reeftofishonly]

So I am researching and contemplating replacing the crushed coral I have in my 155. The crushed coral in there is close to ten years old, and I recently restocked my tank with 6 smaller size fish. I had a nitrate issue about a month ago, and I have been able to lower it to around 40.

First, what are your guys thoughts on crushed coral vs sand?

It is a fish only tank, with about 50 lbs of live rock, and no coral or inverts.


If I do change it, this is the plan I thought about using:

Take out all fish and put in 5 gallon buckets (2 fish for bucket). Remove live rock and place in 5 gallon bucket of current water as well.

Drain water in to large clean garbage cans til it is about 6 inches from crushed coral. At this point, drain remaining water down drain. I currently have 50 gallons of new water ready to go that I was going to use for a water change.

Once water is mostly gone, scoop out crushed coral by hand, cup, dust pan, whatever means necessary. Soak up left over water via towel and place sand down. Replace water from garbage cans back into tank. (PS this water is still very good, I did about 3-4 %70 water changes in passed month.

Then take new water I have ready that I was going to use for my water change. Place live rock back into tank, and when dust settles, re-acclimate fish back into tank.

How does this sound? Any other points I should know to minimize spikes, and what is the potential of losing too much beneficial bacteria from crushed coral? Will live rock seed sand bed in time enough to keep going?

Thanks in advance.

 

[syrinx]

I made a tool out of a large strainer that I flattened the leading edge until it looks like a scoop-really makes the job easy. Crushed coral is much easier to vacume and keep clean than sand, but some people like sand for the asthetic. I think your overall plan of removal is sound- and what I generally do when I replace CC in a tank. The last one I did a couple weeks ago, I did half one week and half the next, but I was replacing coral for coral. Likely your rock will have enough bacteria to avoid any large spikes. And dont fear the dust- most fish do not have issues with it. To lesson it though, I would add water to tank, and then put rinsed sand in a gallon ziplock. Lower the bag to the bottom and gently pour the sand out. There will be 1000% less dust than putting sand in first, and then water on top of it.

 

[reeftofishonly]

I made a tool out of a large strainer that I flattened the leading edge until it looks like a scoop-really makes the job easy. Crushed coral is much easier to vacume and keep clean than sand, but some people like sand for the asthetic. I think your overall plan of removal is sound- and what I generally do when I replace CC in a tank. The last one I did a couple weeks ago, I did half one week and half the next, but I was replacing coral for coral. Likely your rock will have enough bacteria to avoid any large spikes. And dont fear the dust- most fish do not have issues with it. To lesson it though, I would add water to tank, and then put rinsed sand in a gallon ziplock. Lower the bag to the bottom and gently pour the sand out. There will be 1000% less dust than putting sand in first, and then water on top of it.

Thank you so much for the info. From what Ive read, and most my experience in the past was with my 90 gallon reef, the loss of beneficial bacteria, is more of a concern in the reef system as opposed to a fish only system. Is this a correct thought?

Secondly, the fish going into the bucket are a clown tang, soha tang, spiny box, Picasso trigger, rainbow wrasse and seabae clown. How can I ensure success while bucket keeping for a day or so? (Im thinking from start to finish, this should take me 8 hrs or so. Is this a good estimate, or does it need to be a 2 day deal?

 

[reeftofishonly]

Also my main reason for swapping crushed coral out are:

The crushed coral is at least ten years old..if not more like 12. I had a nitrate spike a month ago to nearly 200 (before adding most of new fish) and did a series of water changes to get it down to 40. I also dry vacuumed the sump. Im thinking the crushed coral may be helping the nitrates rise.

Secondly, I am really pondering the idea of getting rid of my trigger and puffer, and acquiring a coral cat shark. I am researching the idea, and from what I have gathered people have kept them in 125s, and so I feel my 155 would be ok, and I am revamping my house and considering buying a used 250 tank that I could upgrade to. I have been told the crushed coral is a no no for bottom dwelling fish including sharks. (Quick note: I initially invest in excellent filtration and still maintain that. I have a 50 gal sump, MTC oversized protein skimmer, 50 lbs live rock and I run two pumps at about 1200 gallons an hour flow total.

I have the means to easily do 30 gallon water changes (20 percent) every week.

So in summation: Taking out coral for sand because 1. Age of coral, 2. friendlier for bottom dwelling fish and 3. Reduce nitrate potential.

 

[syrinx]

Bacteria is more important for fish- remember corals do not really add bioload to the tank, whereas fish do. Many coral tanks are bare bottom after all. If I was budgeting time to do this job, I would think 4 or 5 hours would do it- and I would reintroduce the fish after the tank had been running for a hour or two to clear out a bit of fog. I would not leave them in buckets for any longer than absolutely needed. Keep one fish to a bucket if you can, so aggression is not an issue. Be sure to keep them at a constant temp as well- maybe just jack up the heat in your house while you do it.

 

[syrinx]

yes it is better off not to have gravel with sharks or substrate dwelling or sifting fishes. And yes the gravel could be a issue at that age, or maybe not. I tend to change it at client request, rather than for a chemical issue.

 

[reeftofishonly]

Bacteria is more important for fish- remember corals do not really add bioload to the tank, whereas fish do. Many coral tanks are bare bottom after all. If I was budgeting time to do this job, I would think 4 or 5 hours would do it- and I would reintroduce the fish after the tank had been running for a hour or two to clear out a bit of fog. I would not leave them in buckets for any longer than absolutely needed. Keep one fish to a bucket if you can, so aggression is not an issue. Be sure to keep them at a constant temp as well- maybe just jack up the heat in your house while you do it.

Thanks again. Tank is in my finished basement, and stays around 68. I can place in a room with a space heater to keep constant. What about oxygen levels? Will 3-4 gallons of water hold enough oxygen for 5 hours or so? I know it silly question, considering fish stay in bags with less water during shipping, but I don't want to flirt with the mortality rates of shipping.

Also, shark aside, is the age and the fact that it is crushed coral enough reason to switch? Or is too big of a risk? I have used crushed coral now the whole time, without issue aside from last nitrate spike. I know if its not broke don't fix it, but from what ive read sand sounds like the way to go.

Lastly, for fish only with live rock, is there both an economical and safe sand to use? Ive read live sand (which as a bio major in college, I believe is bogus-the prebagged commercial stuff anyway) If so, where can you get it, and how deep of sand for fish only?

 

[syrinx]

For fish only, unless you are keeping wrasses or other fish with particular needs, depth is entirely up to you. It is decoration unless you are going for a deep sand bed-in which case you should read up on that proccess. I would not get the shark personally, and unless the nitrate issue becomes routine- I would not change the gravel. I would regularly siphon detritus out of it when changing water. Fish in buckets are usually fine for the amount of time you will be working. If you are have concern about O2, on occasion take a glass of water from the bucket, and pour it back in a couple of times. Airpumps on small containers can actually drive off O2, especially if the basement has a higher co2 level.

 

[reeftofishonly]

Ok, I have decided to go ahead and do it tonight. The only thing left to decide is the type of sand..Do I use the courser stuff that looks like crushed coral somewhat that the LFS uses, or do I go Oolite sugar sand. Pros and cons?


And lastly, once the coral is out of the tank, and the tank is bare or coral and water, should I use freshwater to clean the tank out or leave it be?

 

[syrinx]

I would leave it be- that is the bacteria you want! I go for a fairly fine grade-but the sugar sand blows around a lot for the way I do my tanks. I like a regular fine arragonite- usually carib sea. Remember doing projects at night can be risky! Make sure you have everything you need on hand- and extra! Bear in mind also that you can end up with a milky tank if your not careful- although I have never lost fish due to this.

 

[reeftofishonly]

I have everything good to go. Clean garbage cans, carib sea sand, 50 gallons new water ready, siphon, garbage can for coral and buckets for fish.

After sand and water are in tank, how safe after is it to put fish in? should I drip acclimate them as if they were new fish,?

 

[syrinx]

it should be the same as a water change really, so acclimation for temp is the only real issue. Read up on drip acclimation- its really not the way to go for fish often times. For sensitive sea stars shrimps etc it can be vital though.

the biggest issue is to take time rinsing the sand! That and being gentle as you add it to the tank(bag method). Taking time on these steps will save time in the end!

Finally- your tangs are pretty sensiitve fish- and generally not compatible. Keep a close eye on them as they not only are aggressive-but prone to stress related issues.

 

[reeftofishonly]

update

update

Thanks again to Syrinx for helping me along.

No loss of life, water cleared in about 8 hours. 1.5 inch sand bed all around, so far so good.

One concern that lead to a superman story, was during the fish pull process. We pulled 75 percent of the water out into garbage cans, and then pulled the live rock out. We then netted the fish to be put into buckets. The buckets did have some live rock in them as well.

When fish were out I told my father that we only caught 5 of 6 fish. He insisted they were all out, and upon looking through tank with close eye, there were no other fish in tank.

We checked everywhere, the floor, overflows, garbage cans to see if he had been siphoned etc. Still no fish. There was rock in buckets where fish were being held, so again he reiterated he had caught all of them, and being a triggerfish, was probably hiding in one of the rocks.

So we finished pulling water, then crushed coral, cleaned tank with rag using only tank water. We then filled tank, put sand in, and let clear for a few while acclimating fish. As we put the rocks in, which I did not want to do yet because you could not see what you were doing, he said it was getting late and we need to get rocks in so we can place fish in. At that point, they had been in buckets for about 2 hours.

With the trigger out of sight, out of mind, I picked up the final rock on the floor of my basement, for which was there because the containers I had bought were filled to capacity. It was a small rock, 3 lbs or so, and as I handed it to him on the ladder, I heard a sound coming from the rock.

I turned the rock over, and there wedged in a hole of the rock, was the humu (Picasso) trigger still trying to move. He was completely out of the water for nearly 3 hours! Upon discovery, I immediately placed him in the water with the other fish, still lodged in the rock.

At that point, the room temp in basement is 65, and water temp of buckets was 75, ten degree difference, but I felt I had no choice but to get him in water.

We waited to place the fish in tank for about an hour, letting the dust settle in tank, and still the trigger was in rock looking like he had no means to get out (stuck himself pretty good) once acclimation was complete, an hour or so of dripping, we placed all fish in tank including rock with trigger.

An hour later, and still the trigger was in the rock. At this point, I felt something needed to be done or else we would lose the trigger. We took rock out and gently tried to dislodge him, but there was no room for play. Feeling desperate, we felt intervention was necessary, and while rock was in bucket water, took a chisel to the rock, breaking off small sections. We finally broke it enough to free the trigger, and put him in bucket. He swam upside down for about two minutes, before I netted him and put him in tank. Hoping the oxygen in tank along with current, would kickstart him.

Sure enough, within 5 minutes, he vanished into the dust cloud, and this upon waking up this morning, was back to normal eating. Hard to believe, I thought for sure he was a goner.

Learned a valuable lesson about rocks and fish, and also learned as sensitive as fish can be, they are still kindered by mother nature and anything is possible, even 3 hours of water deprivation.

 

[syrinx]

Good deal. I for one like to put rocks into a cloudy tank where I cannot see. The work is less contrived that way-and is perfectly natural. After all, we are no lesser or greater part of nature than a hurricane or a ant from a universal standpoint.