Do our cichlids need water?

[Rod54]

correct me if i'm wrong.... as i may well be, but what about the growth inhibiting pheremones secreted? they must break down over time of course, but into what?and aren't new amounts being added all the time anyway? what gets rid of the amino acids that make up these protein strains?? I always thought diluting them with water changes was the best option?

Water changes are the best option.....but that assumes plentiful water supply.

I'm looking at ozone to break down organic componds....then carbon to filter out the residue....but that doesn't replace trace elements that water changing does!

[laurie]

by strains i meant chains

I would deffinately agree with the rainwater.... i grew up on it, best thing you could ever do (except for maybe the added flouride for our teeth) i don't see why they don't make industry use recycled water and keep the clean water in the creeks and rivers for our fish? or better, limit our demand for water by limiting our population???

[laurie]

Hormones released by fish= in aquaculture the used to drug one female with a hormone called LHRH...[d-Ala6, Pro9 Net]-luteinizing hormone-releasing hormone (LHRH-A) im pretty sure it was a booster, they then secreted pheremones to let the others know they were up for it, and quite large quantities, these however are breeding pheremones, not size stunting ones... interestingly, if you took the fish out.... and used the same water and put new fish in, without drugging one.... they would start spawning too... indicating that the pheremone lasted in the water... we never really tested the longevity of this, however it was effective over at least a couple of hours....

[CThompson]

Coils can remove up to 3mg nitrate per hour - that's fairly impressive in my book.... though obviously there are other alternatives. I've no idea which is better and have no way to judge.

Dave,

You’d I’d say be in a better position to make an educated judgement on this . Here is my layman’s take on it, as I’m sure you’ll have seen me write before;

Bacteria need three things, 1) O2, 2) surface area (to live on) and 3) food (Ammonia and nitrate). Any one of these three things can become a limiting factor = reduces impact on water cycling.

Of course with nitrate reduction you need no 02 so the limiting factors here will be 1) 02 free zone, 2)surface area and 3) food (nitrate).

Seachem denitrate is just a form of biological media, only about the size of kitty litter made smaller to reduce channelling (limiting O2 transportation) and maximising amount of media that can fit in a given space.

From memory, the recommended flow rate through a denitrate filter with Seachem denitrate is something like 20 gph (never have managed to remember the LPH). Where as if I remember correctly, with a coil denitrator it has to come out at the other end at a rate that would correspond to a dripping tap. Fast or slow, either way it is significantly slower rate than 20 gph.

In addition, a coil denitraor has only the inside surface of the coil (hose) itself to provide an area for colonisation. Even a layman such as myself can see that when comparing this surface area with what can be provided by a purpose built biological media, that there is no competition here also. How long would the coil have to be to equal the same amount of surface area provided by say... 4 litres Seachems denitrate? 100 km? 150km? Certainly more than can be provided in close proximity to your fish tank, which realistically you’d be doing well providing 20 meters.

For reason of superior comparative surface area and flow rate with a denitrate filer filled with Seachems denitrate, is why I have always thought a coil denitrate style of reducing nitrates is the lessor choice when comparing which way is better to remove nitrates.

Both methods will remove nitrate, but one will do it at a faster flow rate, and will have more anaerobic bacteria to get the job done (because there is more surface area).

It’s one down side is cost, it will cost a lot more to produce this style of denitrate filter than a coil one. For me, cost is the last to figure into such a decision as at the end of the day, money is still spent, and I for one want the best that can be achieved with that money.

Craig

[YeW]

Craig -

Agreed.... provided they are not limited in their growth by one of more of the other elements required.

I'm all for larger surface area - but the assumption then is they are limited by geography rather than by nutrients. The same applies to the More's law used in aerobic filters. If this is the case then extra surface area may be unnecessary. This is a quandry for which I cannot give you an answer... I simply dont know enough about the bacterial inhabitants of aquarium filters.

David.

Laurie -

The example you give is of a hormone to induce spawning. I guess what I was asking is, is there a hormone that stunts growth? (as is often touted) or is the growth simply limited by a build up of waste?

[laurie]

Dave-

Sorry i can't really help on that one..... I've always heard of it, and during my work with hormone release drugs i thought there MUST be other chemical triggers being released into the water (schooling fish having VERY similar lengths comparative to age would suggest that this occurs) but what my previous reply was trying to explain was that released pheremones deffinately do effect other fish in the water, and they can stay in the water for extended periods of time.

As for the filters... you guys seem to have better insight than me, let me know what you come up with

[GTR73]

For what it's worth, in Brisbane we're on Level 4 water restrictions up here and all it seems to involve at this stage is you can only fill up buckets for watering on designated days (odd numbered houses on Tues, Thurs, Sat; even numbered on Wed, Fri, Sun). If you're caught on the wrong day using your garden tap filling a bucket, you can cop a fine.

But for me it's not an issue yet, I just make sure I do a water change on the appropriate day, using 20L buckets for water changes then water the garden with the used tank water.

a council saying you can't do a water change on your fishtank is like saying you can't give your dog clean drinking water due to water restrictions.

A fellow fishkeeper up here rang the council and they advised we can still do what's necessary for the well-being of our pets, whatever pet that may be. I don't think large fishrooms were specified to the council in that inquiry however.

[CThompson]

I'm all for larger surface area - but the assumption then is they are limited by geography rather than by nutrients. The same applies to the More's law used in aerobic filters. If this is the case then extra surface area may be unnecessary. This is a quandry for which I cannot give you an answer... I simply dont know enough about the bacterial inhabitants of aquarium filters.

The "More's Law" = more is better? I like it, and in regards to biomedia, I must say I'd advocate it. Rather a bit more than is needed than not quite enough eh!

If the nutrients are in limited supply compared to the "geography", then we have achieve our goal in my opinion, as there is no downside (impact wise on fish tank) to this scenario. Where there is a very obvious downside if the reverse were to come about.

How would you work out EXACTLY the amount of media required? Bearing in mind there will be fluctuations in nutrients such as will be brought about as more or less fish as the tank matures, overfeeding/underfeeding etc. It may be theoretically possible to calculate (in laboratory conditions) exactly how much bacteria are required for a given amount of waste/nutrients and work out also exactly the amount of surface area needed to support this bio-load. But coupled with fluctuating demands...would make it even more impractical to try and achieve the exact amount of media required.

The only way we can make sure we have enough media is to over-shoot requirements.

This is a very practical reason why a denitrate filter is better than denitrate coils, as you can have ample media for the bacteria to adhere to. Remembering of course that a coil denitrator doesn’t even have media.

Craig

[YeW]

agreed Craig. The coil is the media .