JM350Z

Hi, I have had my RO setup for a few months but just been using it to top up my 2000 gallon pond now and then. I would like to set it up on a constant trickle. I also have 2 20" jumbo filters so i plan on splitting the water feed in between jumbo filter and RO system then joining again on the exit with a adjustable tap on the jumbo's to adjust the mix.

Does this sound right?

If so when setting the mix adjustment what parameters should i get the exit water to? I have an inline TDS meter i can hook up on the exit.

Thanks

James

Davej

Hi James

Yes T in between the carbon filter and the membrane so you have two pipes feeding water in, this one and the RO water output.

What is the KH and pH of the pond and the supply?

Dave

JM350Z

Supply is ph 8.4 and kh 230

Pond is 8.2 and kh 106

Just to confirm, I should T after jumbo carbon and also after RO system with an adjuster on the jumbo carbon.

Davej

Hi James

Just remind me of the filters on this system please.

Dave

JM350Z

12000 lph pump to large multi bay containing brushes, jap mat then aerated K1 then back to pond.

Also 16000lph pump to multi cyclone to bakki type shower containing 100 litres of cyrstal bio then back to pond.

12 koi all medium size.

JM350Z

All other parameters are perfect. TDS about 150.

What idea TDS and KH should I get the mix to so I can just leave it on a constant trickle Dave?

Davej

Hiya James

Thanks, just checking it wasn’t a Bead.

Put a T in between the Carbon and the RO intake and put a valve in the teed of piece to control the supply water going in. Other feed in is the RO output.

Looks like you have already taken the KH down a fair amount already.

You will need to do a bit of playing to get the mix of supply and RO right.

One approach is to simply continue to feed in RO until the pond KH gets down to around 50ppm and then start mixing but personally I would suggest that you start with a mix that gives you a combined KH of 40ppm for the water going in, to give you a good chance to see how the system performs, this approach takes a little longer but the changes in the water are more gradual..

When you get down to a pond level of KH 40ppm you will need to keep a close eye on things, it should stabilise at something less than 40ppm, what this number will be depends on the particular system, the filters, stock and the feeding and the amount of mixed water you are feeding in.

If the 40ppm mix is too lean/the amount you are putting in is insufficient your KH will end up at zero and you will crash the pH so I’d be looking to tweak the mix up to 50ppm if the KH in the pond fell below 30ppm, if this fails to address the decline in KH then you will have to go for a stronger mix, Aim is to find a balance where the mix/amount going in is sufficient to compensate for the KH burn of the system and you will have a nice stable KH.

Your KH kit needs to be your best friend throughout all of this, and it does require a fairly disciplined approach to testing, good idea to keep a diary in which you can jot down the numbers etc so you can review how things have progressed.

One thing to remember, if you increase the feeding you will probably need to tweak the mix!

Hope this helps

Dave

JM350Z

Brilliant advice, thanks Dave.

I'm using NT labs test kit at the minute.

Is there another that tests Kh more accurately?

Davej

Hi James

I prefer the Nutrafin KH kit, one drop is equal to 10ppm using a 5ml sample of water in the test tube supplied with the kit. If you use a 10ml water sample then its 5ppm per drop.

One of the good thing abouts having low Kh is that a kit goes a long way.

Dave