teebs

The working pressure for my unit is between 35 to 65 psi. Judging from the rejection rate of the RO membrane I am getting 90% compared to the optimal range of ard 95%. Obviously the rating of the RO membrane is based on 60-65psi pressure so from the readings I am getting, I believe the water pressure in my home is probably ard 45-50 psi only. Another issue is that the water passes through the first filter catridge of my crystal pro before entering my RO/DI unit so this might cause some drop in the water pressure also.

TDS reading of NTUC Pure water is ard 1-3ppm. I measured ard 15 bottles previously and this is the TDS range I am getting.

For RO units, you do not need to worry about replacement catridges. The RO membrane is rated for 5,000 gallons, the sediment and carbon filters are rated for 1,500 to 2,500 gallons. The DI catridge is refillable so you only need to get the replacement DI resins. If you are worried about replacement catridges, you can get the full size RO unit and not this portable unit. The full size units uses standard 10 inch catridges which you can get in Singapore easily. I believe the RO units in Singapore typically do not come with DI catridges. DI catridges is usually an add on so it will cost more. Also when buying RO catridges take note whether the membrane is 50, 75, 100 or 150 GPD. There is a lot of difference in the amount of water it can produce per day and also the cost of the RO unit.

According to the supplier, the DI catridge is able to produce approx 500 gallons of 0 ppm water before it needs to be changed. Anyway, the set I got comes with an extra DI catridge, 1.5lbs of MB400 resin good for 4 refills and 1 extra sediment and carbon filter. Total effectively is 6 DI catridges and refills. Based on my total set cost of ard $400, Max volume of 0ppm water that can be produced = 3,000 gallons = 11,400 L Cost of producing 1L of 0 ppm water at max volume: $0.035 Cost of producing 1L of 0ppm water assuming 500L produced: $0.80 Cost of producing 1L of 0ppm water assuming 1,000L produced: $0.40 Cost of producing 1L of 0ppm water assuming 2,000L produced: $0.20 Cost of producing 1L of 0ppm water assuming 4,000L produced: $0.10 Cheapest distilled water: NTUC Pure water @ $1.35 for 4.5L => $0.30/L Crystal Pro unit with 5 refill sets: $198 + $300 = $498. According to my usage 2 Crystal Pro DI catridges can produce ard 240L of 0ppm water before it needs to be changed. Cost of producing 1L of 0ppm water using Crystal Pro = $498/(240x6) = $0.35

Ok, I just took the time for the RO/DI unit to fill up a 1.5L bottle of 0 TDS water. According to my watch, it took 8 minutes to fill up the 1.5L bottle. The waste water produced is this much: Using a measuring container to measure the amount of waste water produced gave approx 2.7L. So 1.8L of waste water produced for every 1L of 0 TDS water produced.

I don't think it happens thia way... Basically it depends on the treated water that is being pumped to our homes.

Bulk order for this will be quite difficult as it is expensive. Shipping cost is also very high.

Later, I will use a 1.5L bottle to time how long it take to fill it up and how many litres of waste water is produced. Actually the rejection rate was slightly lower than expected. According to the supplier, the 100GPD membrane has a rejection rate of 95% at 60psi pressure. So it seems that the HDB supply is less than that.

My tap water is 187ppm just now. In the morning when i did my first batch of RO/DI water, my tap water was 257ppm...

Now for the TDS readings: Tap Water TDS reading: 187ppm TDS Reading after the carbon stage of the RO/DI filter. This is the pre RO stage: 187ppm TDS Reading after the RO stage before the DI stage: 18ppm [From the reading, the RO membrane has a 90% TDS rejection rate] TDS Reading after the DI stage: 0ppm TDS reading of the waste water produced by the RO: 294ppm

Just got my portable 100GPD RO/DI unit recently but decided to reconfigure it into two sets, a sediment filter + carbon filter & faucet adaptor for drinking water and the sediment, carbon, RO and DI unit for aquarium use only. Reason for this is that RO units will have waste water that is usually ard the ratio of 2L+ of waste water for every 1L of RO/DI water produced. Here is the RO/DI unit that I got from USA. The 100GPD RO Membrane made in USA. Current setup of my RO/DI in my toilet. Using the existing Crystal Pro unit to hook up to my water supply as I did not get the hose adaptor from the supplier. Couldn't find the correct size adaptor at hardware stores ard my area. Currently setup as follows: Sediment=> carbon> RO membrane=> DI=> outlet. I'm using the carbon catridge stage of the Crystal Pro unit to connect my RO unit. Basically I took out the carbon catridge so the filter catridge is empty, then I connect the inlet of the RO/DI unit to the back connector of the Crystal Pro.

Not sure if I read it correctly but the temp controller does not have a power cord?

up for the day.

yes, distilled water is the same as RO/DI water. The NTUC brand of distilled water that I used previously had a TDS reading of 1-3ppm so it is definately useable. However, cost wise, buying bottles of distilled water is going to be more expensive than using RO/DI in the long run. Of course if you have a nano/pico tank, then it doesn't make sense to get a RO/DI unit either.

Coral chips are for bringing up the PH of the tank and also acts as a buffer for the PH. So coral chips do not support your bio load. What I would suggest is to replace the bio balls with live rocks.

What did you expect??? Jacky's thread is everything except his tank thread...

upz for the day.

Didn't realize your house got coconut trees...

Ya...but hotel city really difficult to increase levels...

1) Bioballs will only leach NO3 back into the tank if detritus is trapped in them and when the detritus decomposes, then No2 and No3 may be leached into your tank. 2) Sulphur denitrator will help in reducing the NO3 but this will be a long process. Do not expect miracles and hope that the sulphur denitrator will being your NO3 levels down immediately. If you want a faster effect, do a 50% water change and then use AZ NO3/Prodibio Bio Clean to reduce the NO3 levels. 3) If your corals do not show signs of stress, then you may want to monitor them. High NO3 levels do not affect the corals immediately. For SPS, iit is recommended that the NO3 levels be kept within 5ppm.

No warranty for ur iPhone huh??? U sign new contract with new line and terminate ur old line?

U should know wat... weekend => family time => no LFS Night => family time => stay at home

U forgot hotel city...

So many gatherings...

Jacky...U DA man... I have heard of people dropping their iphones into the toilet bowl but this is the first time I heard of anyone cleaning their iPhone by doing a 2-3 hr freshwater dip...