I've stepped over to the dark side

[phin]

I've been keeping a freshwater planted tank for the past 9 months and was fairly successful with it until about 6 weeks ago when I experienced a major genocide in my tank and lost most of my plants as well. So naturally I got a marine set up to try my hand at.

For $75 on craigslist I got:

29 gallon tank w/stand
2 coralife T5 30" fixtures
--2x 31w 10,000k
--2x 31w acitinic
200w in-tank heater
aqua tech 30-60 hob filter
maxijet pump/powerhead
1 bangaii cardinal
1 brittle star
1 emerald crab
1 blud hermit crab

plus: loads of dead coral, salt mix, hydrometer, food, and other extra stuff.

The lady who sold it had a reef tank, but twice had all her coral die off and decided to sell it all than to try a third time.

So, basically, I know very little of what I'm doing. I haven't had a chance to read the saltwater forum yet, but I plan to. But before that, I have some questions...

• How critical is it that I get a skimmer? Would a skimmer allow me to reduce water changes from weekly to monthly or longer, assuming the same population in my tank?
• What skimmer is recommended for a 29 gallon tank?
• Right now I'm going to keep the tank a FOWLR, and I've purchased a small 1/2lb piece of fiji rock, already cured and added it to my tank. how many hours of light a day should I keep on the tank with no coral?
• Since I added the live rock I've noticed a colony of little critters have invaded one of the other rocks in the tank. The critters are 1-2mm long, opaque with little legs and move quite quickly. They appear to be feasting on some reddish looking algae that is on that rock. Any idea what these critters are?
• The temp of the tank is at 82F with lights on and gets down to about 80F with the lights off by morning. The heater is set at 76F so all the heat comes from the lights. What can I do about this, and is it a problem?

I think thats it for now. Hopefully I'll get a chance today to read up on marine tanks. I'm sure more questions will follow.

 

[quaddity]

Good deal!

A skimmer would be good but not absolutely necessary. No sump I'm assuming? So you would need a hang on back skimmer. An Aqua C Remora would be good for the tank. If you don't get one just do a weekly water change. It's not that big of a deal for a 29 gallon. Once your tank is running for a while (more than 6 months) and things are stable you probably won't do water changes as frequently but for the beginning even with a skimmer I'd do a weekly change.

The critters are probably coepods. The fish will eat them when they can catch them they are beneficial to the tank.

Heat is a common problem in saltwater tanks. The lights and pumps can heat the water too much. If the tank doesn't go above 82 degrees you should be ok. If it does you may need a fan to blow on the water and expel the heat from the lights or a chiller if you have $$$.

 

[Lotus]

You may also get a little cooling by having your powerheads directed to the surface a little more, to create some turbulence at the surface.

Weekly water changes would work. Keep an eye on those nitrates. Also, rinse your filter material every week.

 

[phin]

Thanks for the answers so far.

When I got the tank (Friday) I was able to keep all 29 gallons of water. I did a nitrate test saturday and it showed 50ppm. I bought some RO from my LFS - 8 gallons worth - and did the change saturday night. I'll check the nitrates again today and see where they are.

When I rinse the filter media is it ok to rinse in dechlorinated tap water or should it be rinsed in the salt water mix? - Just wondering incase I'm rinsing media without doing a wc.

Since I'm using a HOB filter with floss/carbon cartridges, how important is carbon filtration in my tank? I don't use any carbon in my planted fw tank, is it unpopular in marine tanks?

Is it generally accepted that the more live rock the better? i've got a few large pieces of coral skeleton in there that I could easily replace with live rock. Would there be much of a benefit, isn't the coral skeleton already colonised by bacteria?

The SG in the tank is 1.024. the SG will rise as water evaporates, so just top off with pure RO to keep the SG stable, correct?

 

[quaddity]

Most people with saltwater reef or fowlr (fish only with live rock) tanks do not run any kind of filter. The live rock is the filter. You should have a min of 30lbs of rock in the tank. The coral skeleton is probably "live" if it was in the tank originally. Top off with just RO/DI water is correct. You could run the hob filter with just the filter floss in it and take out the carbon. There's times when you might want to run carbon, phosguard, etc in the filter but not normally. If you keep the filter floss in there keep it rinsed (rinse it in RO water) otherwise it will add nitrates to the tank when it gets full of particles. You could also turn that filter into a refugium and grow chaeto in it.

 

[phin]

wow. 30lbs of live rock...its $5.99/lb @ my LFS. I knew marine tanks cost more, but i guess I just didn't know. I suppose I could add some live rock a few lbs at a time. Until I get enough live rock would replacing filter cartridges after removing the carbon be detrimental as opposed to just rinsing the floss? I guess I'm wondering how much of a roll the floss plays in the bio filter if the rocks/substrate play a larger roll than in a fw setup. I've got a ton of replacement cartridges from the previous owner.

 

[Lorna]

floss is only really good to remove particulates from the water......live rock would provide the biological filtration of choice as it is very porous and is quickly populated with the beneficial bacteria that break down waste in the water. You can add live rock slowly but you will probably have small spikes when you add it as there will be some die off when the rock is exposed to air. Unless you buy it and keep it in water during transport. Your other option is to put filter media such as bioballs etc in your hob filter until you get enough live rock....these can lead to nitrate build up as they become detritus traps which break down to nitrates ....high nitrates such as you have are not directly harmful to fish but they are to the other inhabitants such as snails and inverts.....you can reduce these buy doing frequent water changes until it is down to an acceptable level.

 

[phin]

I think I'll go with the bio balls in the hob and remove the floss cartridges. I hadn't thought of that, great idea. I'll add live rock a bit at a time. I can get LR from my LFS and transport it in a 5gal bucket with water from their tank.

Since I have 2 light fixtures, what I believe to be 120w of light (4 30" T5 tubes), can I just run one of the fixtures, 60w of light (30w of 10,000k and 30w of acitinic), since I don't have coral? Would this be enought light for the microorganisms in the LR to photosynthesize? I figure less light would cut down on the temp increase.

 

[phin]

The pump in my tank is a maxi jet 1200, rated to move 295 gph. Between the pump and the hob do you figure I've got enough flow or should I add another small pump (400 or 600) in the other corner?

 

[TRe]

Keep checkin on craigslist! Im sure you can find someone breaking down there tank and alot of times live rock goes for about $2/lb... Where do you live? Possibly a reef club in you area?

 

[phin]

I'm in Tallahassee. As far as I can tell, no reef club or any kind of aquarium club in the area. maybe I'm looking wrong. I will be down in S.FL during the beginning of June. If I were to pick up some live rock down there and keep it in water in a 5gal bucket w/lid for a day or two to bring it back up here how bad is the die off likely to be? will the rock have to re-cure even if I keep it in the water the whole time?

 

[tanks a lot]

Craigslist is a great idea to find live rock. I agree with getting rid of the floss and going with some bio balls......it sounds like a better fit for what you have. Good luck and welcome to the "dark side"!

 

[phin]

Thanks, I'm looking but I've got to wait for someone to break down their tank and sell the live rock out of it. Right now there are several reef tanks up in my area, but they are all for everything included.

I'd love to set up a top notch tank with sump, refugium, skimmer, etc, but space and (more importantly) money priorities make it very unlikely that any time soon I will be making any major overhaul on this tank. I think adding live rock slowly as I can squeeze some extra change for some and replacing the floss with bio balls are great ideas. I would love to have a refugium growing nitrate eating algae, but turning the hob into a refugium isn't likely. Is there anything that can be grown in the tank that won't be devoured by the clean up critters that will help with eating nitrate?

 

[phin]

So my emerald crab just croaked. He could have been old, since I don't know when he was purchased originally. How sensitive are these guys?

 

[Lorna]

the light you have will be sufficient for the rock and fish etc. It probably won't support corals with maybe the exception of a few polyps such as mushrooms/zoas etc. Some low light corals don't require intense light such as some lobophyllia or acans. Not sure why the crab died but some inverts don't like high nitrates and you do have that. If you purchase live rock and keep it wet it should be okay with minimum die off. Just be prepared for a small mini cycle or better yet get it home and put it in a bucket with saltwater, a powerhead etc for a few days test for ammonia if zero then add it.....shouldn't be a major cure necessary.....good luck. Oh and for what it is worth....this isn't the dark side....it is the bright side. just ask those with metal halide set ups.....much brighter than dark, moody cichlid tanks.....

 

[phin]

Thanks for the info. I've been doing water changes and keeping the nitrates around 12.5ppm. I left the dead crab in the tank since the peppermint shrimp was pretty attached to him and ate him up. Everything else seems to be doing well. The tank came with a small mushroom polyp that has been opening up nicely under the light and a deep purplish brown coral that kind of looks like a tree. At this time I don't plan on adding any more coral, just more live rock.

This may not be the dark side, but is sure it the expensive side...although my uncle broke down his 110 gal w/40gal sump and has offered me the skimmer, when I get down to sfl in a few weeks I'll see if it will fit in my stand. If so I'll build a 10g sump for the skimmer (there won't be enough room under the stand for sump w/skimmer and a fuge).

I'm going to add a green chromis this week (want a cheap damsal) to add some more activity to the tank since the cardinal like to hide, the shrimp only comes out at night, and I only see the brittle star's arms when he's feeding. green chromis should be compatible with the bangaii cardinal, right?