algae, nitrates, lobsters

[natan]

Hey,

It's me again, this time with some positive news at last. My 15g and everyone in it is doing fine - 2 months after cycling. I do have a couple of - perhaps unusual - concerns:

1) Purple algae (bacterial ancestors of our great mitochondria I'm told; they look like slimy purple sheets covering all surfaces) are out of control. What is the best (cheapest) source of RO water?

2) What kind of snails eat the purple algae? I have a blenny fish in the tank who feeds on some kind of small green algae but will refuse anything else. I don't want to completely exterminate all species of algae by very potent algae eaters, as they are in many ways beneficial.

3) Purple reef lobsters do not do well in 15g or smaller tanks. I killed 2 of them with water parameters being close to perfect. Nothing else died, neither inverts nor fish. Every supplier claims they are "extremely hardy" but apparently every invert or fish in my tank could top them. Does anyone know blue spiny lobsters?

4) Lately I had nitrates above 20 ppm. I keep changing 80% of water followed by adding 50% of what remains and removing 50% of that again before filing the tank. This seems to bring nitrates down to zero, as much as I can read. But in a couple of days they are back to 20 - 30 ppm. Any suggestions?

Thank you all!

 

[fishbait]

the algae you are describing sounds like cyanobacteria. if you don't have any corals then kill the lights. low nutrients and high flow, and no lights for a couple days should clear it up. the nitrates could be the cause of the lobster deaths. inverts are highly sensitive to high nitrates.

 

[Bifferwine]

Your algae is slime algae (cyanobacteria). There isn't anything that will eat it.

Check your grocery store, Walmart and fish store for RODI water. If all else fails, you can buy a good quality, cheap RODI unit yourself from Ebay. I got mine from a vendor called PureWaterClub. It's a 6 stage, 100 gallons per day unit, and it was $60 plus $40 shipping. I've been raving about it ever since, it works great.

As for your nitrates, that's a common problem in small tanks like yours.

Here are some questions to answer:
How many fish do you have? Are you overstocked?
Have you checked your new water for nitrates before water changes? Tap water often contains very high levels of nitrates.
What kind of food do you feed, how much, and how often? Flakes and pellets can lead to nitrate problems. You should only feed frozen. Don't overfeed!
Do you have a protein skimmer? Is it a good one, does it work?
Do you run any sort of wet/dry, canister, trickle, power filter, biowheels, bioballs? All those can lead to nitrate problems.
Do you have crushed coral substrate or sand? Crushed coral can lead to nitrate problems.
Are you missing any animals? Dead/dying things can cause nitrate spikes.

 

[natan]

How many fish do you have? Are you overstocked?

Two small fish.

Have you checked your new water for nitrates before water changes? Tap water often contains very high levels of nitrates.

Yes. I am aware of nitrates in the tap water.

What kind of food do you feed, how much, and how often? Flakes and pellets can lead to nitrate problems. You should only feed frozen. Don't overfeed!

Not trying to overfeed. I do use flakes. BAD POINT 1

Do you have a protein skimmer? Is it a good one, does it work?

Nope. No protein skimmers. BAD POINT 2

Do you run any sort of wet/dry, canister, trickle, power filter, biowheels, bioballs? All those can lead to nitrate problems.

I do run a biowheel! Never thought that could be a problem. BAD POINT 3

Do you have crushed coral substrate or sand? Crushed coral can lead to nitrate problems.

The former! I never liked crushed coral, but thanks to my pet store... BAD POINT 3

Are you missing any animals? Dead/dying things can cause nitrate spikes.

No, that has never been a problem.

Thanks a lot, you have been very helpful!

 

[Bifferwine]

Actually, that would be 4 bad points! Ding ding ding! ;)

I'm guessing those are the reasons for your nitrates.

 

[fatman]

You do not mention live rock. That is the typical firt defense against nutrients in a reef tank. One to two pounds per gallon of water is most commonlyreccomended. One with a deep sand beb, up to two wiyhout a deep sand bed.
Crushed coral is only bad in that it esily provide a lot of space for the trapping of detritus. Trapped detritus leads to ammonia, which bemoes nitrite, which becomes nitrate. Crushed coral requires regulaaer vacumning and manual stirring.
Skimmers actually remove organic rathr than turning them into nitrite ans nitrates. Definitely the "in" thing in reefing these days.
Frozen foodis much safer than dried, flaked or pelleted to feed. Thaw out as much as your going to feed and feed only the sizeable particles and not the liquids and fines, unless you have filter feeders such as clams, sponges or corals to eat the really fine particles of food.
Bio wheels are maintenance headaches for a reef tank as they need at least weekly cleaning with tank water outside the tank.

 

[natan]

Uh, yes.

Thanks guys. But can you suggest me about adding send to the existing coral? Is adding send kosher in these situation? I mean, is it gonna impact the population of good bacteria?

I'll switch to frozen food from flakes.

 

[sen5241b]

I've been having problems with nitrates recently too (just over 10 ppm). I picked up a piece of LR during a water change out, not too long ago, and a cloud of detritus came off it! Detritus can smother the LR so that the beneficial bacteria can't do its job. I now use a turkey baster to clean the rock off. You need good flow and a turkey baster to keep your LR clean! Once the detritus is in the water you can use filter floss to get it out.

I also had the red slime cyanobacteria so bad that I had to use Red Slime Remover to get rid of it. I know, everyone says don't use this kind of thing but it was really bad and yes it will come back if you don't deal with the source of the problem.

 

[Bifferwine]

If you add sand to your tank and you already have crushed coral, the sand will eventually make its way to the bottom, leaving a layer of crushed coral on the top, and you'll still have the same problems. If you want to replace the crushed coral with sand, you'll have to remove the crushed coral completely, then add sand to the bottom of the tank. It's a huge pain to do, which is why it's so important to start off with the good stuff (sand) from the start!

The good news is that your tank is very small, so it wouldn't be too hard to get the crushed coral out. You'd have to remove your live rock and some water to a container (like some 5 gallon buckets or a rubbermaid tub), scoop the crushed coral out, put sand back in the tank, then put your rock and water back.

 

[HAWKS12thMAN]

Hey,

It's me again, this time with some positive news at last. My 15g and everyone in it is doing fine - 2 months after cycling. I do have a couple of - perhaps unusual - concerns:

1) Purple algae (bacterial ancestors of our great mitochondria I'm told; they look like slimy purple sheets covering all surfaces) are out of control. What is the best (cheapest) source of RO water? I steal all mine. I take the 5 gallon jugs of culligan water for the water cooler at my job and use it in my tank.

2) What kind of snails eat the purple algae? I have a blenny fish in the tank who feeds on some kind of small green algae but will refuse anything else. I don't want to completely exterminate all species of algae by very potent algae eaters, as they are in many ways beneficial. I have been told nothing eats this stuff by many.......... with that said my sally lightfoot crab eats the stuff any time I have it.

3) Purple reef lobsters do not do well in 15g or smaller tanks. I killed 2 of them with water parameters being close to perfect. Nothing else died, neither inverts nor fish. Every supplier claims they are "extremely hardy" but apparently every invert or fish in my tank could top them. Does anyone know blue spiny lobsters? Are you sure the lobsters are dead. Every person I know that has one only sees them once every three month. I put a purple lobster in my DT tank a month ago and have never seen it since. I know its alive because i found a molt a week ago.

4) Lately I had nitrates above 20 ppm. I keep changing 80% of water followed by adding 50% of what remains and removing 50% of that again before filing the tank. This seems to bring nitrates down to zero, as much as I can read. But in a couple of days they are back to 20 - 30 ppm. Any suggestions? Sorry but I dont mean to be an @$$...... You need a bigger tank. Smaller tanks are hard for anybody to maintain. The paramaters swings are way to extreme. If you do want to keep the small tank might I suggest a 30 gallon sump/ fuge!

Thank you all!

 

[natan]

Bifferwine,

How about removing the crushed corals form all the light exposed areas and replacing them with the sand there?

Also, isn't it dangerous to remove too much of the biological filter? Well, I guess I could buy live sand for that purpose, right?

 

[natan]

I have been told nothing eats this stuff by many.......... with that said my sally lightfoot crab eats the stuff any time I have it.

I've seen them eating all kinds of algae. But my late lobster also had appetite for cyanobacteria and that might have actually killed him.

 

[fatman]

The problem with biowheels and other mechaical biologiacl filters is that they actually work to well at converting organics to nitrates. And then there is the fact that they stop there and do not convert any of the nitrates to nitrous gas. Plus they form a skim of bacterial/organic slime on their surfaces which slough off back into the water releasing a huge amont of nitrates all at one time. You can cover yor crushed coral with fiber glass screen and place your aragonite sand on top of it. However, other than the fact that you already paid for the crushed coral there is no good reason to leave it in your tank. Do not expect any noticeable filtration from a new sand bed for at least a month, and it will take a sand bed of sand sized over four inches in depth to develop the bacteria to procees nitrates into nitrous gas.

 

[natan]

...and it will take a sand bed of sand sized over four inches in depth to develop the bacteria to procees nitrates into nitrous gas.

I have been wondering how long would it take for anaerobic environment to develop in the sand bed of my micro (nano?) system, sufficient enough to convert nitrates to N2 + 02.

Do you think 4 in of sand would do in a 15g?

 

[fatman]

Four inches is at the low end of acceptable for a deep sand bed to do any significant denitrification, and that is with a bed of fine sand. You will start to get some denitrification after around a month, but definitely not enough to allow you to not do water changes. You will be able to start extending the time between water changes after three or four months and if your input of stock remains gradual over that time you can probably be to the point of stopping nearly all water changes due to nitrates within a year. However it is still best to do some water changes to keep trace elements stable and to keep calcium levels and alkalinity levels stable. Usually within a year you will start noticing that your sand level is starting to drop. That will mean that the trace elements and calcium in the sand is now entering your water as your sand is actually dissolving deep within the sand bed in oxygen free areas, which is also great as that is where the denitrifying bacteria live. If this isn't happening by then your sand bed is to shallow. Expect to have to replace from ten to thirty percent of a deep sand bed every year as it dissolves.