View Full Version : Skimmer overflows after big RO/DI H2O change

Larry Soderblom
10/31/2006, 08:57 PM
My son Eric and I have each experienced the following situation after making large (10-to-20%) water changes with RO/DI water. The new water has been mixed with salt and aerated and heated for 24 hours. After the water change our skimmers gush clear foamy water. Is this normal and what causes it?

10/31/2006, 09:08 PM
My tank has never done that. Are you changing the level of the water in relation to the skimmer? What type of salt are you using? What type of skimmer are you using? I'm assuming it's in the sump?

Do you add any additives to the salt mix beside the salt? Typically foaming or overflowing of skimmers is related to food that is added to the tank or other additives or chemicals. If none of those things are happening then you have to look elsewhere.

Does it do it with smaller water changes or only larger? Do you use gloves when changing water and keep you hands out of the water. Typically this will cause the skimmers to not skim well rather than overflow. But it's worth asking. Maybe contamination on someones hands etc.



Larry Soderblom
10/31/2006, 09:46 PM
I have a 150G tank with an ADHI Refugium 45 and an ASM G-3 skimmer. In making up the new water I am using Instant Ocean salt mix only (mixed to s.g. 1.026). No, the water level doesn't change due to the water change because the skimmer is in the first compartment of the refugium. The skimmer overflow condition only happens with larger water changes. I am a fanatic about keeping contaminants (particularly soaps) out of the tank. I always rinse my hands and arms and scub fingernails before touching the water.

I should note that I have a brand new Spectrapure MPDI RO/DI system. The TDS shows 035ppm on input and 000ppm on output. But, perhaps there are are uncharged organic compounds that are released from a very RO/DI new system that the mebrane and resin can't catch (as per Randy's article on RO/DI Systems to Purify Tap Water for Reef Aquaria). Perhaps these are generating the conditions of excessive bubble and foam generation. In any case this situation clears up in a day or so by lowering the level control on the skimmer.
Thanks, Larry

Randy Holmes-Farley
11/01/2006, 06:32 AM
There may be a small amount of organic material in the first bit of effluent from the RO/DI. Maybe that was part of the problem.

If you froth the new salt water, does it make bubbles that stay around for more than a few seconds?

Larry Soderblom
11/01/2006, 07:39 AM
Good idea Randy, I'll set up some new water and froth it tonight.
Thanks, Larry

Randy Holmes-Farley
11/01/2006, 07:55 AM
Try a water change with that water too. It may be a one time effect that is gone. Maybe even due to a little soap or something on a mixing container.

11/01/2006, 05:46 PM
Is the skimmer by any chance a Deltec?? my MCE600, now removed did it on occasion and overflowed all over the place, I have a buddy who has an 851 which does it. If you look on the Deltec forum, it does not seem unusual. They are all Pin wheel by the way.

11/01/2006, 05:49 PM
Did not read proparly, just for interest is your skimmer a pin wheel?

Larry Soderblom
11/01/2006, 06:13 PM
dandydan - No, the skimmer is an ASM G-3 Skimmer. It's rated for 300G and is a pretty standard design (hefty pump with venturii to generate foam in a rising column). Larry

11/01/2006, 08:26 PM
I have an AquaC Ev120 skimmer and I have the same problem. I have the gate valve open and the air valve half open. I get extremely watery (flooded the house the first night it was going) skimmate and have to be extremely careful. The difference between too dry and too wet is an extremely small adjustment. I try not to mess with it! Someday when I am bored I plan on calling the company because it does not seem right. I use Tropic Marin, a 32 gallon brute pail, and nothing else -- no soap. Perhaps the new brute pails leach something in even though they are the food grade ....

Larry Soderblom
11/01/2006, 09:27 PM
Eric and I shared the same new (grey) 32 G Brute tub. I was suspicious because I saw a brown film on the lid after covering the water resulting in condensation and drying. I washed it off with alcohol and rinsed with RO/DI water. Bet that's it. It must be bleeding organic resins. I'll do some tests. Thanks!

11/02/2006, 08:07 AM
Let me know - I have the grey pails too... I have never seen the brown film you spoke of.