Large system water changes

u wud a 10% water change on 1350 lt of water !!!

 

i have a volume of 3000L and i work my water changes to this volume, my sump is 1000L, i see this as part of the system that must be changed

 

I do 10% complete system volume, water changes per week

 

uhm I cannot remember where I've seen the article, but they have done some research on water changes over a one year period and found that changing 30% of the total volume monthly is the most viable option. Does not matter if you do 30 x 1%, 3 x 10% or 1 x 30% over a month period. The end result stays the same, lower nitrates.

They started off with a tank with nitrates at 100ppm with a bio load and over a period of a year doing 30% monthly the nitrates came down to less than 10ppm. I'll see if I can find the article again. Imho it is worth reading if you are unsure if your water changes is worth anything or thinking of stopping water changes in total.

 

Makaeel

Your total system and dont be shy you have a big pond next to you, just suck from there. Us gauteners with synth salt after dosing and all other really have the short end when you flush 500l at between R3 to R4 per liter down the drain.

Carl

 

I have been doing 50l a night at the moment ! Been doing it for 4 days now going onto day #5. Ro and Synth

Anyway Mekaeel I would say it is on the total system volume. No point in skimping.

 

Gavin, why synth and not sea water?

Also is Capt. Watson helping?

 

Cannot get to the beach every day and I want to get rid of my cynao problem. Cappy Watson helped out by giving me some good RO water.

This weekend though I am getting 500 odd litres of NSW.

 

Yeah, took him some RO.

We will be collecting water tomorrow for his taks and my tanks. Mekaeel, you are welcome to join us, will have a dive and a case of beers after.

 

Slightly off topic (sorry Mekaeel!) but would the bioload in your system not be an important factor in determining both volumes and frequency of water changes?

 

I agree with Kevin that bioload etc would be a factor in determining volume and frequency of water changes. My philosophy is: change as much water as you can, as often as you can.

 

I wonder if you can do too many water changes though ? There must be point that you get to where you are taking out too many of the beneficial bacteria ?

 

Dude, your bacteria are generally clinging to your rock, and with us using NSW with bacteria in it, i don't see us being able to do any harm in that way.

 

But if you use synthetic ?

 

IMO what will affect the bacterial population is the fact that their nutrient levels are fluctuating rapidly with every water change. I think that less frequent water changes allows for a more stable bacterial (microbial) population to develop that will be related to the nutrient levels (and bioload) in your system.

 

But if you do more fequent water changes, the dissolved nutrient levels will be much lower, therefore you won't need as much bacterial life.

 

IMO you need to be trying to ahieve a stable system. To achive this with frequent water changes you need to be sure that the water that you are using is "stable" / has limited variation in terms of its chemistry. Given the variablilty in the coastal water quality of KZN, especially in the vicinity of Durban, I don't know if your system will be able to stabilise.

I agree with Smithers comment regarding synthetic seawater though. Here your input water quality may be stable, but the microbial populations levels will be bouncing all over the place in response to changes in nutrient levels.