Men immersing in a Mikveh with a filter:
1. The issues involved:
The use of a filter in a men’s Mikveh touches on a number of Halachic issues:
- Is it considered Zochlin?
- Is the water considered Sheuvim and hence carry a number of issues connected with Sheuvim?
- Does Zochlin and Sheuvim even pose an issue for a man’s Mikveh or are they only relevant to a woman’s Mikveh?
2. Does Zochlin and Sheuvim pose an issue for a man’s Mikveh or are they only relevant to a woman’s Mikveh?
A. Baal Keri:
What is a Baal Keri? Keri refers to an impurity of a man that is caused by his emission of seed, whether nocturnally or in the course of cohabitation. Ezra the scribe instituted that men who have experienced Keri are to immerse prior to learning and prayer. Although this institution is no longer obligatory, nevertheless it is customary of all Jewry to immerse on Erev Rosh Hashanah and Erev Yom Kippur in order to have extra purification prior to the High Holidays. Likewise it is customary of scrupulous Jews to immerse throughout the year the morning after they enter the state of Keri in order to pray in purity. It is customary of Chassidim to immerse in a Mikveh every morning for the purpose of extra purity prior to prayer, as explained in B.
Sheuvim: The issue of Sheuvim is not relevant for men immersing for purification from the state of Keri. To achieve purification of Keri one may immerse in 40 Seah [90 gallons or 332 liters] of even drawn [Sheuvim] water that is in the ground [such as a typical swimming pool]. However it does not help to immerse in a vessel that contains drawn water. Thus in a case of a filter, if the filter is turned off, the Mikveh is valid for a Baal Keri according to all opinions.
Zochlin: There is a dispute regarding whether Zochlin is an invalidating issue for the purification of a Baal Keri. Many Poskim rule that a Mikveh which is Zochlin is invalid for purification of Keri. Others however rule that it is valid for purification from Keri. Practically some Poskim rule one may be lenient in a time of need.
B. Tosefes Taharah:
The immersion in a Kosher Mikveh accomplishes two matters. It purifies a person from the Keri impurity and it adds extra purity to the soul, cleansing it in a form of Teshuvah [i.e. Tosefes Taharah]. According to many Poskim these two aspects and benefits are independent of each other and receive separate laws in a case that a Kosher Mikveh is not available. Regarding the purification from Keri the Sages established that a Kosher Mikveh is not required and hence the immersion in drawn water is valid and Zochlin is disputed if it is valid, as explained above. However regarding the purity added to the soul according to many Poskim it requires a Kosher Mikveh in all regards and does not carry any of the Keri leniencies of Sheuvim or Zochlin. Thus even if the filter is turned off while immersing it would possibly still pose a problem of Sheuvim. Thus in conclusion, from this aspect, it is always best to immerse in a Mikveh that is valid also for the immersion of a woman.
It is best for a man to immerse in a Mikveh that is valid [at least Bedieved] even for women and Keilim, in order to benefit from both purification of Keri and also Tosefes Taharah according to all opinions. Thus it is best to immerse in a Mikveh that does not contain a filter which poses an issue of Zochlin or Sheuvim. If the filter poses a problem of Zochlin and is currently on, then according to most Poskim it is invalid. If the filter only poses a problem of Sheuvim then it is valid for Keri purification but is invalid for Tosefes Taharah according to many opinions.
3. Which filters pose an issue of Sheuvim or Zochlin in a Mikvah?
Today there exist many types of filters of which some have an issue of Zochlin and others do not. Some have an issue of Sheuvim and others so not. The following is an analysis on this subject:
Today there exist many types of filters of which some have an issue of Zochlin and others do not. Some filters remove the water from the Mikveh and new waters then enter. This is considered Zochlin. Other filters simply clean the removed waters and then enter them back into the Mikveh. These filters are disputed amongst today’s Poskim if they are considered Zochlin. Practically regarding a men’s Mikveh some Poskim rule one may be lenient even initially. The above filters are external filters that sit outside of the Mikveh waters. However today there are filters that are placed inside the actual Mikveh and simply pump and filter the water while it is submerged within the water. Many Poskim rule that such filters are even initially valid, even for a woman’s Mikveh.
The positioning of the filter: Even in a case that a problematic filter is used, depending on the filters position, it possibly does not pose an issue of Zochlin. Some Poskim rule that if the Zochlin is occurring in the upper part of the Mikveh, above 40 Seah worth of water, then it is valid for immersion. Others however rule the Mikveh is invalid even in such a case. Practically regarding a woman’s Mikveh we rule that initially one is to be stringent to avoid a problematic filter from anywhere in the Mikveh, however Bedieved we rule that the immersion is valid. However regarding a men’s Mikveh some Poskim rule one may be lenient even initially. All the above is regarding the filter removing the water from the Mikveh. However the part of the filter that enters the water back into the Mikveh some Poskim rule is not a problem of Zochlin at all and hence there is no relevance as to where this part of the filter is positioned. Other Poskim however are stringent that it has a status of Zochlin and hence the positioning of the entrance of the water has relevance to the above dispute. Practically regarding a men’s Mikveh some Poskim rule one may be lenient even initially.
Turning off the filter: In all cases that a problematic filter is used, if the filter is turned off during immersion it no longer poses a problem of Zochlin.
Many filters are not just a mere tube but contain a tank that holds and filters the waters. This causes the water to become Mayim Sheuvim. The following problems related to Mayim Sheuvim are applicable when using a filter:
- Natal Seah Venasan Seah.
- The water that re-enters does not become validated [as the Mikveh is Zochlin and has Koach Adam].
- The entire Mikveh becomes invalid due to it receiving three Lugin of Mayim Sheuvim while it is invalid due to Zochlin.
C. New tube filter that is submerged within the Mikveh:
Today there are filters that are made up of a mere tube with filtering material that the water passes through and do not contain a tank that holds the water. Since the filter does not hold the water, it does not pose an issue of Sheuvim. Also, since the filter is submerged within the water and hence does not remove the water from the Mikveh, it does not pose a problem of Zochlin. Such filters are valid even for a woman’s Mikveh, and have already been installed in many Mikvaos of women and men under strict Rabbinical supervision. However some Poskim are stringent even regarding this form of filter. The Mikvaos under the Rabbinical authority of the Eida Hachareidis and Rav Landau do not contain these filters.
List of filters and their law:
Internal filter submerged in Mikveh water
Many Poskim permit even initially, even for women
External filter, removes and returns same water
Most Poskim prohibit, some lenient by men’s Mikveh
External filter removes and new water enters
Invalid even for men’s Mikveh according to most Poskim while the filter is working.
Pumps out water
Invalid even for men’s Mikveh according to most Poskim.
New water entering into Mikveh
Some rule may be lenient by men’s Mikveh
 For a discussion on this matter see: Mikveh Mayim 2 “Kuntrus Mikveh Im Filter” of Rav Yermiyahu Katz; Minchas Yitzchak 3/64
 Zochlin refers to running water, such as the water of a river, stream, running bathtub, or Mikveh with its water stopper removed etc. Zochlin is Biblically invalid for a women’s Mikveh. Thus the question here is does a filter which causes the water to run consider the Mikveh as Zochlin. [201/2
 Sheuvim refers to all water that has entered a vessel and is Rabbinically invalid for a women’s Mikveh. [201/3]
 Rama 581/4; Admur 606/11; See the previous supplement !
 See chapter 88 and Mefarshim there!
 606/11; 88/1
 As this immersion for the purpose of purifying oneself from the state of Keri is valid even using drawn water. [ibid]
 606/11; 88/1 [in parentheses]; M”B in name of Rav Akiva Eiger; Stringent opinion in Gemara Brachos 22b; See Piskeiy Teshuvos 88 footnote 44 for a discussion on this matter.
Other Opinions: There is an opinion in the Gemara ibid that rules a vessel is valid for a Baal Keri.
 Mechzeh Avraham 13 based on M”A 159/27 and Admur 159/22 as explained in Machatzis Hashekel 159 regarding Tevilas Yadayim for bread; Zichron Yehuda 2/62; Vayaan Yosef 46; Beir Moshe 5/21; Minchas Yitzchak 3/64; Piskeiy Teshuvos 88/6
 The reason: They rule that Zochalin [running water] is invalid for purification of a Baal Keri just like it is invalid for a Halachicly required immersion [i.e. Nidda; Ger; Vessels]. [Yoreh Deah 201/2] The proof that Zochlin is invalid for Keri is from the fact the Machatzis Hashekel ibid explains that the reason the Raavad is lenient to allow immersing hands in 40 Seah of drawn water [see Michaber 159/16; Admur 159/23] is because it is valid for a Baal Keri. Thus we see that regarding Zochlin, it is invalid even for a Baal Keri and therefore even regarding Tevilas Yadayim there is question as to whether it is valid. The reason to differentiate between Sheuvim and Zochlin, that Sheuvin is valid while Zochlin is not, is because according to most Poskim Zochlin is a Biblical requirement while Sheuvim is only Rabbinical, and hence by a Baal Keri we are lenient only regarding Sheuvim. [Beir Moshe ibid]
 Arugos Bosem brought in Teshuvah of Zichron Yehuda, brought in Minchas Yitzchak 3/64
 Beir Moshe 5/21; Minchas Yitzchak ibid
 Shalah Hakadosh Yuma p. 288; Minchas Yitzchak 3/64; Kinyan Torah 1/33; See Igros Kodesh 9/353; Igros Kodesh brought in Shulchan Menachem 1/143; Igros Kodesh Rebbe Rayatz 2/142 distinguishes between the two matters regarding pouring and Mishnayos.
 Shalah; Minchas Yitzchak; Kinyan Torah brought in previous footnote.
 Shalah Hakadosh Yuma p. 288; Minchas Yitzchak 3/64; Kinyan Torah 1/33; Mishneh Yosef 4/3 [that initially one is to use a Mikveh that is Kosher with all the Hidurim].
Other Poskim: Some Poskim are lenient and rule that the leniencies of Sheuvim [and Zochlin] apply even when one immerses for Teshuvah or Tosefes Taharah. [Munkatcher in Divrei Torah 9/83; Torah Leshma 375 [of Ben Ish Chaiy]; Piskeiy Teshuvos 88/6] Nevertheless even the above Poskim are initially stringent [Darkei Chaim Veshalom 356; Piskeiy Teshuvos ibid]
 There are numerous types of filters available on the market today, some which do not pose a problem of Sheuvim at all.
 Minchas Yitzchak 3/64; Kinyan Torah 1/33; Mishneh Yosef 4/3; Piskeiy Teshuvos 88/6 [that initially one is to use a Mikveh that is Kosher with all the Hidurim].
 See Mikveh Mayim 2 p. 70-71
 See Minchas Yitzchak ibid
 Igros Moshe Yoreh Deah 1/110 rules it is not considered Zochlin as rules the Rivash, brought in Rama 201/50, that if the water that leaves the Mikveh flows back into the Mikveh it is not considered Zochlin. Others however argue on the comparison to the law there, as in this case it is the filter that returns the water to the Mikveh and it is thus not returning on its own. [Betzeil Hachachma 4/98; Mikveh Mayim p. 71]
 Beir Moshe 5/21
 Beir Moshe 5/21; Mikveh Mayim p. 84 and p. 17; Piskeiy Teshuvos 88/6
Background and other opinions:
Such a filter is not an issue of Zochlin according to all as the water never leaves the Mikveh. [Mikveh Mayim p. 84 and p. 17; Piskeiy Teshuvos 886] Likewise if the filter is made in a way that it does not hold the water but is simply a tube with filtering material that the water passes through, then it also does not pose an issue of Sheuvim. [ibid] Nevertheless many of today’s Poskim forbid such a filter for a women’s Mikveh due to Zochlin. [Kol Korei in Kisleiv 5767; Brought in Kuntrus Mikveh Al Gabei Haotzer of Rav Boaz Lerner p. 59] Likewise these filters can also pose a problem of Sheuvim due to their filtering cloth.[ibid]
 Michaber Yoreh Deah 201/50 based on Rosh
 It is disputed as to whether this validation according to this opinion applies to the entire Mikveh or only to the area below the filter. The following Poskim rule it applies to the entire Mikveh, even above the filter: Tashbatz 1/17; Lechem Visimla 201/86; Tzemach Tzedek 164/5; Divrei Malkiel 3/64; Chibur Taharah 2/41 [however he retracts his ruling in Eimek Sheila 55]; Chavalim Benimim 3/58. The following Poskim rule it only applies to the area below the filter: Mahrik 156; Eimek Sheila 55; See Mikveh Mayim 2/1 for a full discussion on this matter.
 Opinion of Rabbeinu Shimshon and Tur brought in Rama 201/50; See Mikveh Mayim 2 p. 3-4 for a full discussion on this matter.
 It is disputed as to whether this invalidation according to this opinion applies to the entire Mikveh or only to the area of the filter and above. The following Poskim rule it applies to the entire Mikveh, even below the filter: Mordechai; Rashba; Tur; Tzemach Tzedek 176/3-3 [however see 165/4]; Eimek Sheila 55; Gidulei Taharah 60; Lechem Visimla. The following Poskim rule it only applies to the area above the filter: Eshkol [Mikvaos 60]; Tashbatz 3/34; Kinas Sofrim 75; See Mikveh Mayim 2/1 for a full discussion on this matter.
 Rama 201/50
 Beir Moshe 5/21 writes that one may be lenient for a Baal Keri like this opinion [even though the Rama 201/50 is stringent initially like the opinion of Rabbeinu Shimshon]. See Mikveh Mayim 2/1 for a full discussion on this matter regarding a women’s Mikveh.
 Meiy Shiluach 2/8; Lechem Vesimla 201/15; Arugas Bosem 211; Beis Yitzchak 2/29-3; Shoel Umeishiv Riviasa 3/47; See Tzemach Tzedek 164/7
 Divrei Chaim Mikvaos 5; Chazon Nachum 69-71; Doveiv Meisharim 1/69; Minchas Yitzchak 1/149; See Darkei Teshuvah 201/13 and 280
 Beir Moshe 5/21
 See Mikveh Mayim 2 p. 72-74
 Igros Moshe 1/110 based on Rambam, brought in Shach 201/63
 Har Tzevi 177
 Lechem Vesimla 201/192; see Mikveh Mayim ibid
 Mikveh Mayim p. 84 and p. 17
 Beir Moshe 5/21; Mikveh Mayim p. 84 and p. 17; Piskeiy Teshuvos 88/6
 It was authorized by the Rabbanut Hareishit to be used by women Mikvas and was installed in men Mikvas in Mikvas in Elad and other cities. It received the blessings of the following Rabbanim: Rav Mordechai Eliyahu; Rav Shmuel Wozner; Rav Shlomo Amar; Rav Levi Yitzchak Halprin of Machon of Technology
 Some of today’s Poskim forbid such a filter for a women’s Mikveh due to Zochlin. [Kol Korei in Kisleiv 5767; Brought in Kuntrus Mikveh Al Gabei Haotzer of Rav Boaz Lerner p. 59] Likewise these filters can also pose a problem of Sheuvim due to their filtering cloth which may be considered a vessel according to some Poskim.[ibid based on Piskeiy Dinim of Tzemach Tzedek 201/15]