Please visit our Sponsors

FAQs About Water Evaporation, Make-Up H20:

Related Articles: Marine Water Change, Captive Seawater Quality, General  Marine Maintenance

Related FAQs: Make-up Water 1, Water Changes for Marine Systems 1, Make-up Water: Rationale/Use, Gear, Frequency/Amount, Techniques, Water Quality/Adjusting, Trouble/shooting, & Top-Off System s, Controllers, Treating Tapwater Marine Water QualityMarine Plumbing


Top off water and Testing for RO Water TDS 4/27/09
Bob and the Gang,
<Hello Joe>
Hope all is well.
My 135 G Reef tank loses a lot of water due to evaporation.
I add a fair amount of RO water to top it off weekly.
<Am I to understand you top off the tank once a week? Or do you mean you lose a lot of water over the course of a week. If you are topping off only once a week I suggest you try to do it more often, the longer you wait before topping off the tank, the larger the swings in the specific gravity of the water your tank will experience>
<There are auto top off devices available to top off the tank for you and provide a more consistent environment for your tank inhabitants. Search 'ATO' on the Google search box at the bottom of WetWebMedia.>
My question is, should I be adding something to my top off water? Never thought I had too, but I've read a
couple of places where they recommended adding something to keep the PH up.
<It is possible to buffer the water, but not necessary, assuming you are testing and adjusting alkalinity as needed. Just continue adding topping off your tank with RO water, pH swings will be less noticeable if top offs are done on a small consistent scale like with an ATO. You can also aerate your top off water to remove CO2 from it prior to use.>
Also, how can I be sure that my RO unit is working properly (I have the Coralife Pure-Flo)? Is there something I can use to test the RO water? I was reading about TDS testing but wasn't sure if that was necessary.
<I would highly recommend testing the Total Dissolved Solids from the effluent hose of your RO unit. Membranes do lose their potency over time from normal use, but this can be accelerated depending on what chemicals your city adds to the water. Testing TDS is one of the most simple ways of checking the quality of effluent coming from a RO unit, and basic TDS meters can be had at a very low cost.>
<Your welcome.

Re: Top off water and Testing for RO Water 4/27/09
Thanks Josh. Yes I'm topping off roughly every week. I usually lose close to 10 gallons a week! You make a good point about trying to do it more often to avoid larger swings in specific gravity. I'll definitely try to
do that.
I'll also look into a TDS tester.
Thanks again.
<Your welcome, I think you will come to enjoy not carrying full buckets of water around. Josh>

Salinity and water changes  10/25/07 Hello, I would like to start by saying that your site and staff members have been essential in helping me maintain a healthy saltwater aquarium for many years. <fabulous> I recently upgraded to a 125 gallon tank which I plan to maintain as FOWLR. I have about 150 lbs of LR and a 6 in. live DSB, SG will be kept around 1.022. <This is too low. Although most fish can tolerate lower salinities, the micro-crustaceans and other inverts which put the "live" in live DSB and live rock need a salinity much closer to natural sea water (ideally, 1.024-1.026). Please see here: http://www.wetwebmedia.com/spg_salinity.htm> The tank has been drilled and drains into two connected sumps (30 & 20 gallons respectively). The 30 gallon houses a refugium with a live DSB, LR, and two types of macro algae. The 20 gallon has been divided into two chambers, one with my remora protein skimmer and the other holds a Rio 1300 return pump. My livestock consists of 1 juvenile Koran Angel, 1 Powder Brown Tang, 1 Tiger Wardii Goby, and about 40 Nassarius snails. Since this will be my first adventure with a tank this size, I was seeking your advice concerning husbandry. Given the inhabitants and system, how much water should I change on a weekly basis? <5 to 10% weekly or 20 to 40% monthly. Please see here: http://www.wetwebmedia.com/water.htm> Also, do you recommend keeping the SG relatively low if I do not plan to add corals? <No, please see above.> Thank you for your time and advice. Kiet
<De nada,
Sara M.>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: