tds meter reading

[andy rose]

I have just purchased a TDS meter so i dipped it straight into the pond to see the result and have got a very scary result of 930mg/l .
Has anyone got some ideas on how to decrease this reading

[bekko]

what it the reading in your tap water?

[andy rose]

my tap water reading is 370

[MikeM]

Andy: Before any useful suggestions can be made, I think we need to know about your maintenance procedures and stocking levels..... How many gallons? How many/size of fish? Exposed to leaf drop from trees etc? Size & frequency of water changes? Describe filter system.

[andy rose]

hi mike

Thanks for offering some feed back

The pond is 9500 gallons (british).It has two seperate filter systems in which the first vortexs have been converted to take answers,the next two vortexs on each system contains jap mat.at present the pond has 18 koi and some babies from last years spawnings .I will however be having a clear out in the spring and the pond will then contain 14.The average size is probably 25 inches the smallest being 21.5in and the largest 29.5in most are in the middle .

i am currently doing a modification to the system in which i will be pumping out of the last filter on one of the systems with a 16000 liter pump over a three tower shower unit containing 60 kg of bakki media and then returning it to the first filter of the same system.

the pond has zero ammonia, usually a touch of nitrite(0.0658mg/l) and nitrate is currently around 40mg/l, ph is at 7.5.

[dick benbow]

Andy,
Do you run a constant 24/7 trickle of water in from your well/city water?
or do you have a regular routine where you clean, drain water and replace?

[andy rose]

Sorry forgot about maintainance each of the six vortexs is pulled daily and the first ones have a more vigorus regime in which they are cleaned weekly of all sediment by way of a long pull and sweeping everything towards the drain or totally emptying and washing out.The filters are cleaned twice a year each in the spring and in the autumn.I also vacumn but being a bloke not often enough!

[MikeM]

You seem to have plenty of filtration, but you are not indicating water changes beyond what is needed to replace water dumped from the vortexes. I do not know how much water that is, but I expect it is relatively small amounts compared to the pond volume and inputs. The nitrate level is nothing to be worried about per se, but indicates a build-up of organics.

If you are not doing regular water changes, I'd recommend that you start regimen of weekly changes, but at least alternate weeks, especially during warm periods when you are feeding regularly. Start with a 10% water change and gradually increase to, say, 30% until you get the TDS level where you want. Then you may be able to edge back to a 10% water change per week. I do 50% per week, which is relatively extreme. There is a thread on water changes that I'll find & bring up for you, if I can find it.

[Bob Hart]

Andy,

It looks like you have a decent size pond there and keep it well maintained. I see you mention a Bakki shower in your posts, so I guess you've been reading a lot of Mike Snaden's information as well?

I dont run an RO plant, but do use a TDS to measure the difference between my tap water and the pond water, the difference being 'other' dissolved organics. I try and maintain a 20-30 TDS difference, which to me means my pond is very clean. But as Mike and Dick have indicated, to keep this low level I like many people always have a trickle of water going into the pond. This overflows to waste, helping to keep the TDS difference low.

I have 10,000 gallons and trickle in 400-500 gallons per day of purified water. My starting TDS is 260, pond is usually 280/290, even in the Summer when feeding heavier.

If you were to carry out some large water changes and trickle in purified water at say 5% per day, I'm sure you'd see the 930 reading start to drop down to nearer your tap water. May take a while, but it will get there with your current filter maintenance continued.

[Maurice]

Isn’t it funny, we can have a thread here showing a TDS meter is a useful tool, yet over at NI, it’s a worthless piece of kit!

Sorry Jim!
Maurice.