OUsnakebyte October 7, 2003 October 7, 2003 How would I go about doing this? I have a 75 gallon (2 years old) with about 2 inches of coral gravel. I was thinking of changing to sand, but not sure I want a DSB. Maybe just one or two inches of live sand. I don't really like the look of the bare bottom tank. I'm thinking of doing this b/c my nitrates are too high, about 40 ppm, and I change about 15 gallons of water (RO/DI, IO salt) a week. There is never so much as a dent in the rates. I can't get them to come down. I have two maroon clowns, blue tang, yellow tang, and a dwarf angel. I feed once a day, and it is usually a lite feed at that. The rest of the livestock is lps, a few sps, and softies corals. The lps still seem to open up ok, I would just really like to get the rates down to at least 20ppm. I thought about changing the substrate b/c I've heard that food and detritus can easily sink to the bottom between the large pieces of gravel, thus raising the nitrates. I'm not having a problem with unwanted algae at all, probably b/c the tangs keep it mowed down. Anyway, has anyone ever done this? What are the logistics? Do you think it would help? I certainly don't want to send my tank back into cycle. Any thoughts or experiences are certainly appreciated. Thanks, Mike
michaelg October 7, 2003 October 7, 2003 There really isn't an easy way to do this. You could start slowly removing what is there (ok to leave some behind)- best to do in conjunction with water changes, then start a few bags of sugar grain sand in some buckets with some live sand and salt water. Skimm off the scum that will form at the top of the water. After a couple weeks, add to tank. I would use a large funel and a piece of 2-3" PVC pipe. The seeded sand should settle right down without too much of a dust storm. The base of the live rock will get burried a little, but that's OK. I would shoot for 3"s if you want NNR to occur, you need the depth to achieve the anoxic zone needed for the final step in de-nitrification. An alternate method, that may or may not appeal to you, is to put 6-8 inches of sand in a 5 gallon bucket, put the top on, and make a flow through container (small pump feeding from sump, and some sort of drain to return to sump)- you want a fairly low flow going through it). This is described in more detail in Calfo's first book- he was a pretty big proponent for this sort of method. Yet another option is a refugium with a DSB and macro algae to suck out the nitrates.
OUsnakebyte October 7, 2003 Author October 7, 2003 Do you think that would help bring the rates down? I only suggested changing to sand b/c I'm at a last resort here. I'm tired of changing so much water every week and not seeing any improvement. In fact, I'm down right jealous of all you who only change 10 gallons a month!!! :D Space is also an issue. I don't think I can fit a refugium in my dinky one bedroom apartment (wouldn't pass the girlfriend test...). My setup is a 75 Oceanic RR with the Oceanic 20 gallon sump that has the Bio Balls and external return pump (does that make any sense at all?). I guess I could get rid of that sump and pump and add a larger sump with sand, macroalgae, etc. Might be easier than changing the substrate though...? Any thoughts?
ReefMon October 7, 2003 October 7, 2003 You said the magic words... Bio Balls = nitrate factory My guess is if you pull the Bio Balls your problems will go away. You'd want to pull them slowly, a few at a time so the live rock & gravel can slowly ramp up to provide all your biological filtration. HTH Glenn R
OUsnakebyte October 7, 2003 Author October 7, 2003 REALLY!!! I did not know that! Well, I'll try that before I go disturbing my entire system. Thanks Glenn!!! By the way, that sinularia is doing great!.
quazi October 7, 2003 October 7, 2003 Depending on your sump design, it may be an easy switch to make it a fuge. A fuge does not have to have much in the way of sand. Just add some plants and some LR. The key is too make sure the return pump does not suck the plants up. Of course, if you can add some sand in there, so much the better. Just add a light over the sump and leave it on 24x7. You do not need a fnacy light, many people use "home depot specials" for their lighting. An 18 watt florecent light should do it. Just my 2 cents.... :O
Marty October 7, 2003 October 7, 2003 In addition to pulling the bioballs, you can add some sand directly to the crushed coral you have. Do it slowly, say 1/4" at a time and use the technique Michael suggested with the PVC tube. Add it to the top of the cc and it will settle between the grains eventually. Get some nassarius snails and maybe a conch or two to stir things up too. With an established 75g, you probably can get by with one 50lb bag of Southdown (or whatever it's called now) sand from HD. mc
OUsnakebyte October 7, 2003 Author October 7, 2003 Ok, so I think I'll do this... start pulling the bio balls a few at a time. Once they are all gone, I can fill the sump up with more water (the oceanic sump has a recommended fill line, pretty low if you ask me...). Then add some calurpa and a few pieces of live rock for it to attach to and a light. Hopefully this will help those darn rates... Any suggestions on species of macroalgae? Thanks everyone for your help. This a least gives me somewhere to go. Cheers! Mike
michaelg October 7, 2003 October 7, 2003 Chateomorpha (sp?). The spaghetti algae is far and away the best species to keep.- make sure there is some kind of way to prevent stray algae from going into your return pump.
Grav October 8, 2003 October 8, 2003 I've heard the arguments, but I still don't understand this wet/dry = nitrate factory idea. Nitrates are a product of waste. Bio-balls, bio-wheel or whatever wet/dry system you have speed the process from amonia to nitrate, and can't go further. You can only have as much nitrate as the amonia that WAS in the system produces when it breakes down. My question is, how coud bio-balls prevent nitrates from being broken down by the LR, LS or whatever you have in place to do the anerobic resperation? I have the large Tetra-tec on a 33g tank with 4 fish and a good size BTA. My nitrates are 0, I atribute that to an over powered skimmer, and good LR and LS. What am I missing?
Sph2sail October 8, 2003 October 8, 2003 As I understand it, essentially the bio-balls out compete with the natural filter system in LR and LS. They process the Amm -> Nitrite -> Nitrate faster and overbalance the system. With the bio-balls present, you have Nitrates in abundance and the LR and LS have to process more, not less, as the Nitrates would not hit the system at all if you allowed the LR and LS to deal with the whole cycle. hoping I got this right. s
ReefMon October 8, 2003 October 8, 2003 It's 2 different types of biological filtration systems: Wet Dry's & Bio balls host aerobic bacteria and that gives you a partial cycle: Ammonia-Nitrites=nitrates. This is still the best solution for systems without natural filtration, the down side is you must do waterchanges to remove the nitrates. Live Rock and DSB's host anaerobic bacteria, this gives you the complete cycle: Ammonia-Nitrites-Nitrates=nitrogen gas. The beauty of this is the final product is a gas that naturally escapes the system.
Guest October 8, 2003 October 8, 2003 Do you have a skimmer on your system? If not that would help with your nitrate problem.
OUsnakebyte October 8, 2003 Author October 8, 2003 Yea, got a skimmer. It produces a good cup of sludge every week. My girlfriend says she is disgusted that she use to play with the foam oin the beach when she was a kid, now that she knows what it is... :D Anyway, I got home last night and took out about one third of the bio balls. I'll probably wait a week or so before I take out another chunk. Anyone want these things when I'm done? I'm just gonna chuck 'em. Oh yea, about the spaghetti macro... do you think one NO 50/50 bulb would be enough light? I have an extra 24" strip light that's not doing anything right now. Thanks everyone! Cheers, Mike
Sph2sail October 8, 2003 October 8, 2003 I sold my wet/dry with bioballs on eBay. I think I got $37 plus shipping for it. Sold the whole unit w/out a pump. s
michaelg October 10, 2003 October 10, 2003 I would do 2 24W strip lights. You can get plant bulbs for about $5 at home depot, and these work well for refugia. Else use the one and find some sort of PC light at home depot. Michael
OUsnakebyte October 10, 2003 Author October 10, 2003 Actually, I just remembered that I have a twin tube NO with one 10000k and one actinic I'll try to use. It's a 4 footer, but it will be hidden under the stand anyway. As for the substrate, I think I will go ahead and try to switch out the gravel to sand, after I get the bio balls out and chaetomorpha settled in, of course. I like the look of the sand much better. I will go slow, of course, changing a small section of the tank each week. So, about sand. I have a 29 gallon that has about 2-3 inches of Fiji live sand that was going to be a sea horse tank (captive bred only!!!), but that fell through (didn't pass the girlfriend/apartment space issue) ??? Anyway, I have been adding a little bit of water from my weekly changes to it to keep it wet. I thought that would be the best way to keep it "live" instead of letting it dry out, since I couldn't keep it in my tank. I know I will obviously need more, so my question is... If I get some Southdown, or other sand that is not currently "live," is there any way to make it "live" before I add it to my tank? If so what is the best way? Should I put it in the 29 with the Fiji and wait a few weeks? Any ideas??? Thanks, Mike
michaelg October 10, 2003 October 10, 2003 yes- add it to the other live sand How live is it? Do you see worm tracks? Any stratification (lighter zones and darker zones? Are you feeding it?
OUsnakebyte October 10, 2003 Author October 10, 2003 Not sure about the tracks. I'll check closer when I get home. I just add a little tank water each week from my 75. What else should I be doing to keep it live? It's got all kinds of detritus in it. Also, how long will it take for the other stuff to become live? Should I be getting aragonite (sp?) sand to supplement the Fiji? What type of sand (brand, etc.) do you recommend?
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