skimmer why?>

[henward]

you know, i look at thediet of my jardinii, freshwater carnivore, lots of meat for this baby.

say i had one fish, same size tank. one is tropical freshwater wiht a dient of shrimps.

the other was tropical saltwater. diet of the same shrimp. fed exactly the same and same amount.

why is that i would need a skimmer for saltwater?

everyone so far has told me that i nee a skimmr.

pet shp said its not absolutely neccesary. i will put no coral and fancy stuff, just one fish.

hey said it should be ok. cos they have tanks with no skimmer tats salt water and they can succesfully put animls in there..

why is it that i need a skimmer. when freshwater doesnt need it. is it because of the salt water?

all i want in there are a crap load of coral rock for bacteria infestation. and maybe one salt water puffer fish

[reef]

sure you dont need a skimmer, just make sure you do weekly water changers

[henward]

ok

i see, so wiht out a skimmer, the only trade off is frequent water changes.

so wiht a skimmer - in essence, it buys you time to not do water changes.

so lets say without a skimmer, do a water change ever week

with a skimmer under completely identical factors, say every 2 weeks? 3 weeks?

[reef]

In a closed aquarium you need to export waste. skimmers does this to a large degree, so does water changers.

With a good skimmer it will remove waste faster thus less waster changes.

maybe you will only need to do water changers once a month,.

More food you put in the tank the more waste you have to remove otherwise the fish will swim in poo and get sick,

[henward]

ok i see

so basically skimmers are good cos it does give you that ability to take the waste out leaving the water cleaner, same as water changes, but.... no water changes just the actual crap coming out.

ok

i understand, so not neccesary but good to have, and wiht out it one must endure plenty of water changes.

ok cool i get it

thanks

[reef]

yes basically.

Also the skimmer adds a lot of oxygen to the water

[wasp]

Skimmers remove waste not included in the nitrogen cycle such as phosphate and heavy metals, by removing organics that contain these substances.

Water changes will dilute pollution, but not enough. They may be as good as having a crappy skimmer, but they cannot be as good as having a high quality skimmer. Here’s why :-

To make an example, let’s say each week in the fishfood, there is a certain amount of undesireable heavy metals, phosphates, and other nasties added to the tank that are not removed by the nitrogen cycle. We will call this weekly amount one unit of nasties. So during the week, one unit of nasties is added to the tank. Let’s say ½ gets absorbed into the substrate, and ½ remains free in the water. (In reality more than ½ will get absorbed into the substrate but to make it simple we’ll say only ½). Let’s say at the end of the week we do a 50% water change. This will remove ½ the ½ of a unit in the water, or ¼ of a unit, leaving ¾ of a unit of nasties in the tank. The next week another unit of nasties is added to the tank, ½ is absorbed by the substrate, ½ remains free in the water. The tank now contains 1 ¾ units of nasties. We do another 50% water change which will remove ½ of the ¾ of a unit that is free in the water. However the total in the tank is still higher than it was a week ago. In this way, even with a 50% weekly water change, concentration of nasties will continue to increase, even the nasties free in the water increase by simple mathematics, never mind the substrate, and will inevitably reach harmful levels sooner or later.

A few points though, a skimmer is not the total solution either, but if it’s a good one and running 24/7, it will give results superior than can be possibly achieved by even huge water changes. Nasties will be absorbed into the substrate, but will be in balance with the amount of nasties in the water. With a decent skimmer that can hold nasties free in the water down to low levels 24/7, the amount absorbed into the substrate will remain at a low level also, the two balance against each other.

In addition to this a skimmer aerates the water, which also holds pH up.

Having said all that, you CAN get away with no skimmer. But there will be issues, which in a fish only tank will be algae, lower pH, less than clear water, and poorer fish health. But it CAN be done.

Henward, I know you don't want to get a skimmer. And right now you probably hate me.

But trust me, one day you will thank me! :lol:

[tHEcONCH]

Incidentally, as soon as I do a water change the skimmer begins to export waste - I don't know if it is coming from the 'fresh' water, or if it is picking up stuff dislodged by the change itself.

[slappers]

Incidentally, as soon as I do a water change the skimmer begins to export waste - I don't know if it is coming from the 'fresh' water, or if it is picking up stuff dislodged by the change itself.

yes i get that too useing ASW my skimmer goes a little carzy for a while. and im useing RODI

[Ianab]

I think the main reason for skimmers on Marine tanks is that water changing isn't as easy.

With freshwater you can just change the water from the tap and keep your water quality up that way. Heck you can change 50% a day if you want. Or rig up a trickle/overflow system to constantly change it. Why bother setting up an exotic filter system when you have clean water in the garden hose?

With marine tanks the salt water takes more time to mix up and costs actual money, so it's more practical to look after it with more sophisticated filtering and change it less often.

Cheers

Ian

[Ianab]

To make an example, let’s say each week in the fishfood, there is a certain amount of undesireable heavy metals, phosphates, and other nasties added to the tank that are not removed by the nitrogen cycle. We will call this weekly amount one unit of nasties. So during the week, one unit of nasties is added to the tank. Let’s say ½ gets absorbed into the substrate, and ½ remains free in the water. (In reality more than ½ will get absorbed into the substrate but to make it simple we’ll say only ½). Let’s say at the end of the week we do a 50% water change. This will remove ½ the ½ of a unit in the water, or ¼ of a unit, leaving ¾ of a unit of nasties in the tank. The next week another unit of nasties is added to the tank, ½ is absorbed by the substrate, ½ remains free in the water. The tank now contains 1 ¾ units of nasties. We do another 50% water change which will remove ½ of the ¾ of a unit that is free in the water. However the total in the tank is still higher than it was a week ago. In this way, even with a 50% weekly water change, concentration of nasties will continue to increase, even the nasties free in the water increase by simple mathematics, never mind the substrate, and will inevitably reach harmful levels sooner or later.

Eventually it will reach a stable level.

In your example, when your tank has 4 units of 'nasty' you will be removing 1 unit in each water change. That unit will build up again during the next week and be at 4 again for the next change. Say it was PPM of Nitrate and it was 40, do a water change and it's 30, it goes up 10 in a week. So you can hold the level of pollution at (hopefully) harmless levels.

Having said that, the skimmer will let you keep it lower with less water changes, so is a good thing to have.

Cheers

Ian

[tHEcONCH]

Don't forget that skimmers only work on salt water (unless you have a million dollar sewerage treatment plant) - if they did, I suspect you would see them on freshwater tanks. At the end of the day you need to do all you practically can to keep the water clean - whatever method(s) you choose.

[reef]

you can get some small skimmer that are designed for freshwater.

[davidb]

http://www.tmc-ltd.co.uk/pond/sander-freshskim.asp

[wasp]

Strictly mathematically, yes, you are correct. But in real practise what happens is that these substances continue to accumulate in the substrate and exert an influence on the rest of the tank. Actually I'll have to contradict somewhat my mathematical example, having read it again it is less than perfect because it is strictly maths, and ignores some of the other processes going on in a tank, however to some extent the idea does apply, but not strictly mathematically.

Also, the other observations made by the last few posters are valid points.

But end of the day, going without a skimmer can be done, my own first tank ran with quite a few fish and no skimmer for several years. But there will be issues, it is a trade off. I'd say if someone wants to do it and a skimmer is not an option, go ahead, but leave the design open for a skimmer so at some future point one can be added if finance or whatever allows.

Also Henward, hope you realise the bit about hating me was an attempt at a joke !

[davidb]

Alot of people run skimmerless tanks with the ecosystem method, which is something you can look into Henward... Only problem is that Miracle mud is bloody expensive!!! The ecosystem method is not really used by any reefers in NZ but overseas it is very big...

[wasp]

Actually that raises a good point, with the ecosystem the export is done via macro algae and carbon instead of a skimmer, these 2 methods could be used even without going the whole miracle mud system.

However it is telling that after many years of telling people the advantage of going Miracle Mud is that a skimmer is not needed, they are now producing their own brand of skimmer to go with the system (as an option), albeit a fairly weak skimmer.

Another thought is that skimmers are primarily about achieving the needed water purity for corals, fish are much less demanding and a skimmer is not so essential if fish only are to be kept.

[reef]

The ecosystem method is not really used by any reefers in NZ

Are you sure, More people have ecosystem method that hobbyist keeping SPS coral.

I tried it and it worked ok, the only reason i stopped was that my sump was too small to support my tank load, Maybe the next tank will have MM with a skimmer working at night.

Hollywood fish runs it on the coral tanks and it seems to be working as all the coral look good, the show tank in Mt roskill seems to be going well.

The stuff is ecxpensive to buy, but it cheap as you dont add any other supplement other than calcium/kh buffer.

[henward]

but it looks like the most practical and easiest way is a skimmner

though a hang on one is 400 dollars:S

might be easier to buy a new tank or just drill a hole and make an over flow

but then you still hve to buy a skimmer

[tHEcONCH]

but it looks like the most practical and easiest way is a skimmner

though a hang on one is 400 dollars:S

might be easier to buy a new tank or just drill a hole and make an over flow

but then you still hve to buy a skimmer

If you buy good quality gear to start with you will be rewarded in the long run - your tank will run much better, your livestock will be happier, and last longer. It doesn't take too many dead fish and corals before the cost of a good skimmer seems cheap.

[slappers]

get a good skimmer it will cost but it will last years and your tank will thankyou for it

[nemines]

i didn't used to have a skimmer, i used to do 10% water changes every three days but when i went on holiday a lot of my corals died because the nitrates rose. then i got a deltec mce300 for my nano 70L tank couple of months ago. it works wonderfully, its in my bedroom and hasn't caused any problems for studying or sleeping as it's virtually silent. it pulls out about 150mL of gunk a week, and my nitrates are at zero as far as the test can show... id really recommend a Deltec, they're brilliant!

i now know that i can go away for a week and my tank will be fine.

[slappers]

[JoeBlog]

I just bought my 2nd ap902! 8)

DELTEC!

[slappers]

gees i envy you all i got is a AP701 what did you do with the other one