TDS reading

[richg315]

So with battling the Bryopsis problem in my tank i wanted to cover all my bases so checked my water:

Tap Water - 165
RO/DI - 9.4

I know we all strive to have a 0 TDS reading, but since ive had my ro/di machine ive only been able to get it close to 0. Even with a membrane flush and new filters the best its ever been is 5. My question is: Is 9.4 good enough for having a healthy tank? Is this part of my algae problem? Ive been very successful in keeping both sps and lps but my main concern is my algae problem.
Rich

 

[pascal32]

Can you post a picture or describe your RODI system? If you have DI as the last stage your TDS coming out should be 0 if it is not exhausted. If you are using non-color changing resin consider moving to the color changing resin, just a buck more and it is quite convenient!

I would strive to get your TDS below 3, preferably at 0 - mine is about 3 coming off the RO unit and 0 going out of the DI.

I posted a bit on this just yesterday: http://reefcentral.com/forums/showpost.php?p=19669704&postcount=4

Is this fueling Brypsis? probably not helping. as a collective you should keep phosphate under .03 and nitrates under 5 for SPS (just my opinion), though many folks run higher on nitrates with no issues.

For the brypsis some folks raise the MG level using Kent MG supplement - you must use the Kent brand for this. The success rate has been high, which is somewhat troubling - what is it about Kent Mg that makes the Brypsis die? what other effects can this have?

 

[mgdth]

Check your phosphates...

 

[der_wille_zur_macht]

It's hard to guess at tank problems based on a TDS reading because TDS does not discriminate between harmful stuff and harmless stuff. A non-zero reading COULD indicate the source water as your problem, but it's not a given. Still it may be worth solving the TDS "problem" to see if it helps with your algae battle.

How are you measuring TDS? Right out of the unit, or after the water has been stored in a container? How is the water getting from the unit to your tank? Are you making small batches or large batches? If you are constantly making small batches, TDS creep could be an issue - see the other thread, it's discussed there.

In general though algae problems are basically caused by an established population of algae getting fueled by nutrients. Whether you solve the nutrient problem at it's source or by pulling more out of the water (GFO, bigger skimmer, other methods) you need to eliminate the nutrients. Sure, you could go test for values, but the presence of an algae problem means you have elevated values, so test kits aren't going to give you information you don't already have - though they may be useful in solving the problem, since you'd be able to test nutrient values in the RO/DI water, and/or in freshly mixed saltwater, to see if either are contributing.

Next step - physical removal of as much algae as possible, and add appropriate herbivores to eat the rest. Cleanup crews won't solve the algae problem since it'll just keep growing if your don't take care of the nutrients, but they can help by disrupting an established population of invasive algae.

 

[richg315]

Thanks for the replies guys! Currently my Mag is over 1600 with Kent Tech-M which is slowly starting to take care of the Bryopsis. It looks like my problem is a mix of that and regular hair algae.
I usually make small batches of water, so that might be part of the problem. Now that you guys mention it my CUC has dwindled to a couple crabs and a handful of snails, so today i'm going to beef them up to help me combat the problem. I will also test my nitrates and phosphates today to better understand where the nutrients are coming from. Thanks for posting guys!!!
Rich